All practice questions

Match each public sector reform scenario with the structural policy instrument it illustrates.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Removing statutory monopoly rights matches Deregulation; Transferring all government equity matches Outright Privatization; Mandating profit generation with zero operating subventions while remaining state-owned matches Full Commercialization; Charging user tariffs to cover operational costs while receiving capital grants matches Partial Commercialization.

Each economic policy instrument addresses a distinct structural aspect of public sector reform. Opening state monopolies to market competition constitutes deregulation. Transferring public equity completely to private investors defines outright privatization. Mandating financial self-reliance and profit generation without state subventions under continued government ownership represents full commercialization. Finally, funding operational expenses internally while relying on government for capital development grants defines partial commercialization.

Step-by-Step Solution

1

Analyze ownership and legal framework changes in each reform scenario.

Identify whether the reform involves selling state equity, eliminating market entry barriers, or altering enterprise financing mechanisms.

Privatization impacts ownership, deregulation impacts market entry rules, and commercialization impacts financial autonomy.

2

Differentiate full commercialization from partial commercialization.

Full commercialization requires total operational and capital self-sufficiency without subventions, whereas partial commercialization relies on state capital grants for structural developments while funding daily operations internally.

The presence of state capital subventions distinguishes partial commercialization from full commercialization.

3

Pair each enterprise scenario with its corresponding policy instrument.

Match power sector entry removal with Deregulation, hotel share sale with Outright Privatization, transport agency subvention withdrawal with Full Commercialization, and water board capital grant assistance with Partial Commercialization.

Each operational scenario aligns strictly with a specific public sector restructuring policy.

Key Concept

Classification of Public Enterprise Reform Policies (Privatization, Commercialization, and Deregulation)

Question 6782Question →

Consider the conversion of iron(II) chloride to iron(III) chloride in aqueous solution:

2\text{FeCl}_{2(aq)} + \text{Cl}_{2(g)} \rightarrow 2\text{FeCl}_{3(aq)}

Which of the following statements correctly explains why the conversion of

\text{FeCl}_2

to

\text{FeCl}_3

is classified as an oxidation process under both classical and modern concepts of redox?

Classically, iron(II) chloride gains an electronegative element (chlorine); modernly, the oxidation state of iron increases from +2 to +3 due to the loss of an electron.

Classically, elemental chlorine undergoes oxidation because its oxidation number is +1; modernly, iron(II) ions gain electrons to form iron(III) ions.

Classically, iron(II) chloride loses oxygen to chlorine gas; modernly, chlorine gas is oxidized because it accepts two moles of electrons per mole of molecules.

Classically, the process represents an acid-base neutralization reaction; modernly, iron(II) chloride acts as a dehydrating agent by eliminating net positive charge.

Show answer & explanation

Answer: Classically, iron(II) chloride gains an electronegative element (chlorine); modernly, the oxidation state of iron increases from +2 to +3 due to the loss of an electron.

Answer

The conversion of iron(II) chloride to iron(III) chloride is an oxidation process because classically, it involves the addition of an electronegative element (chlorine) to iron(II) chloride, and modernly, iron undergoes an increase in oxidation number from +2 to +3 via electron loss.

The correct answer accurately contrasts classical and modern definitions. Under classical rules, adding an electronegative element like chlorine to a compound constitutes oxidation. Under modern rules, oxidation is defined by electron loss and an increase in oxidation number, which occurs when iron(II) with an oxidation state of +2 loses an electron to become iron(III) with an oxidation state of +3.

Step-by-Step Solution

1

Analyze the reaction using classical redox definitions.

Classical redox extends beyond oxygen/hydrogen transfer: oxidation is defined as the addition of an electronegative element (such as chlorine) or removal of an electropositive element. In

2\text{FeCl}_2 + \text{Cl}_2 \rightarrow 2\text{FeCl}_3

,

\text{FeCl}_2

gains a chlorine atom (electronegative element), making it an oxidation process.

Classical definitions account for reactions not involving oxygen or hydrogen by tracking electronegative and electropositive additions/removals.

2

Analyze the reaction using modern electronic and oxidation state concepts.

The ionic half-reaction for iron is

\text{Fe}^{2+} \rightarrow \text{Fe}^{3+} + e^-

. The oxidation state of iron increases from

+2

in

\text{FeCl}_2

to

+3

in

\text{FeCl}_3

.

Modern theory defines oxidation as the loss of electrons (LEO) resulting in an increase in oxidation state.

3

Synthesize classical and modern findings to identify the correct statement.

The statement identifying chlorine addition as classical oxidation and

\text{Fe}^{2+}

to

\text{Fe}^{3+}

electron loss as modern oxidation is correct.

Both classical and modern frameworks independently confirm that

\text{FeCl}_2

undergoes oxidation.

Key Concept

Classical vs Modern Definitions of Oxidation and Reduction

Estimated Time:2m 0s

Question 6783Question →

Match each product or market scenario in Column A with its most appropriate channel of distribution in Column B.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Fresh perishable produce matches Producer → Consumer; Custom industrial boilers match Producer → Industrial User; Mass-produced packaged detergent matches Producer → Wholesaler → Retailer → Consumer; Imported specialized luxury watches match Producer → Agent → Retailer → Consumer.

Fresh perishable agricultural produce requires direct sales (Producer → Consumer) to reach the final consumer before spoiling. Custom-built industrial machinery demands direct sale to industrial users (Producer → Industrial User) due to high technical specifications and custom design. Mass-market detergent requires a multi-stage channel (Producer → Wholesaler → Retailer → Consumer) to break bulk and reach millions of households nationwide. Imported luxury items use exclusive agents (Producer → Agent → Retailer → Consumer) who specialize in regional distribution without holding inventory title.

Step-by-Step Solution

1

Analyze product physical characteristics and target market breadth for each item in Column A.

Identified perishable goods, technical industrial goods, mass consumer goods, and specialized luxury goods.

Distribution channel length depends directly on product perishability, technical complexity, unit value, and market size.

2

Select the optimal channel structure corresponding to each product's logistical and sales requirements.

Paired short/direct channels with perishable and high-tech industrial goods, and longer intermediary channels with mass-market and agent-handled goods.

Direct channels prevent decay and handle complex specifications, while indirect channels provide wide distribution reach and specialized market representation.

Key Concept

Channels of Distribution Selection Criteria

Estimated Time:1m 30s

Question 6784Question →

In a holding-subsidiary business combination, the subsidiary company completely surrenders its separate legal entity status and ceases to exist as a distinct corporate body once the holding company acquires more than 50% of its voting shares.

True

False

Show answer & explanation

Answer: False

Answer

False. A subsidiary company retains its separate legal entity and corporate existence after being acquired by a holding company.

The correct position is False because acquiring a majority of voting shares creates a parent-subsidiary relationship without liquidating or extinguishing the subsidiary's legal personality.

Step-by-Step Solution

1

Define the structure of a holding and subsidiary relationship.

A parent (holding) company acquires a controlling shareholding—typically over 50% of voting stock—in another company (the subsidiary).

Establishing the mechanism of control helps differentiate business combination types.

2

Determine the legal status of the subsidiary post-acquisition.

Unlike a complete merger or statutory absorption, the subsidiary remains a separate legal personality capable of suing, being sued, and operating under its own registered name.

Maintaining distinct corporate entity status is the defining legal feature separating holding-subsidiary structures from complete corporate absorptions.

Key Concept

Retention of Separate Legal Entity Status in Holding-Subsidiary Relationships

Question 6785Question →

A DC supply with an electromotive force (e.m.f.) of $24.0\text{ V}$ and an internal resistance of $2.0\text{ }\Omega$ is connected across three identical $12.0\text{ }\Omega$ resistors connected in parallel. What is the terminal potential difference across the battery in volts?

Show answer & explanation

Answer: 16

Answer

The terminal potential difference across the battery is

16.0\text{ V}

.

The three identical

12.0\text{ }\Omega

resistors in parallel combine to yield an equivalent external resistance of

4.0\text{ }\Omega

. Adding the battery's internal resistance of

2.0\text{ }\Omega

gives a total circuit resistance of

6.0\text{ }\Omega

. The total current drawn from the battery is

I = \frac{24.0\text{ V}}{6.0\text{ }\Omega} = 4.0\text{ A}

. The terminal potential difference is the voltage drop across the external circuit,

V = 4.0\text{ A} \times 4.0\text{ }\Omega = 16.0\text{ V}

.

Step-by-Step Solution

1

Find the equivalent external resistance of the three parallel resistors.

R_p = 4.0\text{ }\Omega

Three identical resistors

R = 12.0\text{ }\Omega

connected in parallel have an equivalent resistance of

R_p = \frac{12.0}{3} = 4.0\text{ }\Omega

.

2

Find the total circuit resistance by adding internal resistance to the parallel combination.

R_{total} = 6.0\text{ }\Omega

Internal resistance

r = 2.0\text{ }\Omega

acts in series with the external parallel combination:

R_{total} = R_p + r = 4.0 + 2.0 = 6.0\text{ }\Omega

.

3

Calculate the total current supplied by the cell.

I = 4.0\text{ A}

Using the circuit formula

I = \frac{E}{R_{total}}

, we divide the e.m.f. of

24.0\text{ V}

by the total resistance of

6.0\text{ }\Omega

.

4

Compute the terminal potential difference across the cell.

V = 16.0\text{ V}

The potential drop across the external parallel network is

V = I R_p = 4.0\text{ A} \times 4.0\text{ }\Omega = 16.0\text{ V}

, which equals

E - Ir = 24.0\text{ V} - (4.0\text{ A} \times 2.0\text{ }\Omega) = 16.0\text{ V}

.

Key Concept

Terminal Potential Difference and Internal Resistance

Estimated Time:1m 30s

Question 6786Question →

An aqueous mixture passes completely through standard filter paper without leaving any residue, but its particles are retained when passed through a parchment (semi-permeable) membrane. When illuminated by a narrow light beam in a dark room, the mixture scatters light, and under an ultramicroscope, its particles exhibit continuous zig-zag movement without settling under gravity. Which of the following correctly classifies this mixture and describes the characteristic behavior of its dispersed phase?

It is a colloidal system, and its particles undergo electrophoresis toward an oppositely charged electrode when an electric field is applied.

It is a true solution, and its particles will rapidly precipitate if a small amount of an electrolyte is added.

It is a suspension, and its particles undergo rapid gravitational sedimentation upon standing for a few minutes.

It is a colloidal system, but its particles lack any net surface charge and cannot be coagulated by adding ionic compounds.

Show answer & explanation

Answer: It is a colloidal system, and its particles undergo electrophoresis toward an oppositely charged electrode when an electric field is applied.

Answer

The mixture is a colloidal system whose dispersed particles carry electric charges and migrate toward an oppositely charged electrode during electrophoresis.

The mixture exhibits all hallmark physical and optical characteristics of a colloidal system: particle size between

1\text{ nm}

and

100\text{ nm}

(retained by parchment membrane but passing filter paper), Tyndall effect (light scattering), Brownian motion, and surface electrical charge that allows directional movement in an electric field (electrophoresis).

Step-by-Step Solution

1

Analyze permeability and filtration behavior

Passing through standard filter paper rules out suspensions (

>100\text{ nm}

). Retention by parchment (semi-permeable) membrane indicates a particle size between

1\text{ nm}

and

100\text{ nm}

, characteristic of colloidal systems.

True solution particles (

<1\text{ nm}

) pass through both filter paper and semi-permeable membranes.

2

Analyze optical and kinetic behavior

Scattering light (Tyndall effect) and random continuous motion (Brownian motion) without settling confirm colloidal properties.

True solutions do not scatter light (no Tyndall effect), while suspensions settle out under gravity.

3

Determine electrical properties of the colloidal system

Colloidal particles preferentially adsorb ions from the medium, acquiring a net positive or negative surface charge. When subjected to an electric field, they migrate toward the electrode of opposite charge (electrophoresis).

Surface charges prevent colloidal particles from aggregating under normal conditions and make them responsive to electric potential.

Key Concept

Physical distinction and electrical properties of true solutions, colloidal systems, and suspensions

Estimated Time:1m 30s

Question 6787Question →

Match each type of insurance policy on the left with its corresponding coverage description on the right.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Endowment Assurance Policy matches with payment on maturity date or death; Hull Insurance Policy matches with coverage for physical damage to a vessel's structure and machinery; Consequential Loss Policy matches with compensation for lost earnings and standing charges due to fire interruption; and Employer's Liability Policy matches with protection against legal liability for employee workplace injuries.

Each policy is paired with its exact commercial description: Endowment Assurance covers life protection and savings payable on maturity or death; Hull Insurance covers physical vessel damage; Consequential Loss covers loss of profits and fixed costs following fire disruption; and Employer's Liability covers legal claims from workplace injuries.

Step-by-Step Solution

1

Identify the core feature of Endowment Assurance

Endowment policies combine life assurance protection with a savings component, paying out at a designated future date or upon earlier death.

This distinguishes endowment policies from whole life policies.

2

Identify the scope of Hull Insurance

Hull policies in marine insurance specifically safeguard the ship's physical structure, engines, and fixtures against maritime risks.

Marine insurance separates ship/vessel cover (hull) from cargo or freight cover.

3

Analyze Consequential Loss in Fire Insurance

Consequential loss policies cover secondary economic damages like lost profits and standing overheads while operations are stalled after fire damage.

Standard fire policies cover direct physical property damage, while consequential loss covers indirect financial impact.

4

Determine the application of Employer's Liability

Employer's liability policies belong to accident insurance, indemnifying employers for compensation owed to workers injured on the job.

It addresses legal duties under labor and work-injury compensation legislation.

Key Concept

Classification and scope of coverage across Life, Marine, Fire, and Accident insurance policies.

Question 6788Question →

The solubility of copper(II) tetraoxosulfate(VI), $\text{CuSO}_4$ , at $60^\circ\text{C}$ and $20^\circ\text{C}$ is $40.0\text{ g}$ and $21.0\text{ g}$ per $100\text{ g}$ of water respectively. Calculate the mass of $\text{CuSO}_4$ in grams that will crystallize out of solution when a saturated solution containing $250\text{ g}$ of water is cooled from $60^\circ\text{C}$ to $20^\circ\text{C}$ .

Show answer & explanation

Answer: 47.5

Answer

The mass of

\text{CuSO}_4

that crystallizes out of solution is

47.5\text{ g}

.

Subtracting the solubility at

20^\circ\text{C}

(

21.0\text{ g}

) from the solubility at

60^\circ\text{C}

(

40.0\text{ g}

) yields

19.0\text{ g}

of

\text{CuSO}_4

deposited per

100\text{ g}

of water. Multiplying by the ratio of actual solvent mass to reference solvent mass (

250\text{ g} / 100\text{ g} = 2.5

) gives

47.5\text{ g}

.

Step-by-Step Solution

1

Determine the mass of

\text{CuSO}_4

deposited per

100\text{ g}

of water on cooling.

40.0\text{ g} - 21.0\text{ g} = 19.0\text{ g}

per

100\text{ g}

of water.

The mass of solute precipitated per

100\text{ g}

of solvent is equal to the difference in solubility between the higher and lower temperatures.

2

Calculate the mass of solute deposited for

250\text{ g}

of water.

19.0\text{ g} \times \frac{250\text{ g}}{100\text{ g}} = 47.5\text{ g}

.

The amount of solute crystallized out is directly proportional to the total mass of solvent present.

Key Concept

Crystallization and Mass of Solute Deposited on Cooling

Question 6789Question →

Under a national economic reform program, a government-owned seaport authority was restructured to operate as a self-sustaining corporate entity aimed at making profit, without any transfer of equity to private investors or removal of state ownership. Which structural reform policy does this transformation illustrate?

Commercialization

Outright privatization

Market deregulation

Indigenization

Show answer & explanation

Answer: Commercialization

Answer

Commercialization

Commercialization is the policy where state-owned enterprises are restructured to operate strictly on commercial principles to earn profit and remain financially independent, while the state retains full ownership.

Step-by-Step Solution

1

Analyze the features described in the scenario.

The enterprise is restructured to operate commercially for profit and cover its expenses, but government ownership is entirely retained.

Identifying the ownership status and operational mandate distinguishes public sector reform policies.

2

Compare the scenario features against definitions of economic reform policies.

Operating public corporations as profit-making corporate bodies while keeping state ownership is the exact definition of commercialization.

Commercialization changes operational focus and management autonomy without changing ownership.

Key Concept

Commercialization of Public Enterprises

Estimated Time:1m 0s

Question 6790Question →

A mixture containing

28\text{ g}

of nitrogen gas (

N_2

) and

12\text{ g}

of hydrogen gas (

H_2

) reacts to completion according to the equation:

N_2(g) + 3H_2(g) \rightarrow 2NH_3(g)

What mass of the excess reactant remains unreacted at the end of the reaction?

[N = 14,\ H = 1]

6.0\text{ g}

16.0\text{ g}

10.0\text{ g}

3.0\text{ g}

Show answer & explanation

Answer: $6.0\text{ g}$

Answer

The mass of the excess reactant remaining unreacted is

6.0\text{ g}

.

The correct answer is

6.0\text{ g}

.

28\text{ g}

of

N_2

corresponds to

1.0\text{ mol}

, while

12\text{ g}

of

H_2

corresponds to

6.0\text{ mol}

. According to the equation

N_2(g) + 3H_2(g) \rightarrow 2NH_3(g)

,

1.0\text{ mol}

of

N_2

consumes

3.0\text{ mol}

of

H_2

. Therefore,

N_2

limits the reaction, and

3.0\text{ mol}

of

H_2

(

6.0\text{ g}

) remains unreacted.

Step-by-Step Solution

1

Calculate the initial number of moles for each reactant.

\text{Moles of } N_2 = \frac{28\text{ g}}{28\text{ g/mol}} = 1.0\text{ mol}

;

\text{Moles of } H_2 = \frac{12\text{ g}}{2\text{ g/mol}} = 6.0\text{ mol}

.

Converting given masses to moles is necessary to apply stoichiometric coefficients.

2

Determine the limiting reactant using the mole ratio from the balanced equation.

The reaction ratio is

1\text{ mol } N_2 : 3\text{ mol } H_2

.

1.0\text{ mol } N_2

requires

3.0\text{ mol } H_2

. Since

6.0\text{ mol } H_2

is available,

N_2

is the limiting reactant and

H_2

is in excess.

Comparing available mole ratios against stoichiometric requirements identifies which reactant is completely consumed.

3

Calculate the unreacted moles and mass of the excess reactant (

H_2

).

\text{Unreacted moles of } H_2 = 6.0\text{ mol} - 3.0\text{ mol} = 3.0\text{ mol}

.

\text{Unreacted mass} = 3.0\text{ mol} \times 2\text{ g/mol} = 6.0\text{ g}

.

Multiplying unreacted moles by the molar mass of

H_2

yields the remaining mass.

Key Concept

Limiting and Excess Reactants in Stoichiometry

Estimated Time:1m 30s

Question 6791Question →

An official of a marine insurance company carefully examines the risk details of a cargo vessel, evaluates the potential financial exposure, determines the appropriate premium rate, and decides the terms under which coverage will be granted. Which insurance process or concept is being performed by this official?

Underwriting

Reinsurance

Co-insurance

Indemnity

Show answer & explanation

Answer: Underwriting

Answer

Underwriting is the correct concept, as it refers directly to evaluating risk, calculating premiums, and establishing policy terms.

Underwriting is the core insurance function in which an underwriter evaluates the degree of risk presented by a proposer, decides whether to accept it, sets the policy conditions, and calculates the premium rate.

Step-by-Step Solution

1

Analyze the actions taken by the insurance official in the scenario.

The official is inspecting risk factors, assessing loss probability, fixing premium charges, and establishing acceptance conditions.

Identifying the operational steps helps match the scenario to its standard insurance terminology.

2

Compare the actions to insurance concepts.

Evaluating proposal risk and determining terms is known as underwriting. Reinsurance and co-insurance deal with risk sharing, while indemnity is a compensation principle.

Distinguishing between risk evaluation and risk sharing mechanisms leads to the accurate answer.

Key Concept

Underwriting Concepts in Insurance

Question 6792Question →

Consider the chemical reaction represented by the equation:

BF_3 + NH_3 \rightarrow F_3B:NH_3

Which of the following statements correctly describes the role of

BF_3

in this reaction according to acid-base theories?

It acts as a Lewis acid by accepting an electron pair.

It acts as a Brønsted-Lowry acid by donating a proton.

It acts as a Lewis base by donating an electron pair.

It acts as an Arrhenius acid by producing hydrogen ions in aqueous solution.

Show answer & explanation

Answer: It acts as a Lewis acid by accepting an electron pair.

Answer

Boron trifluoride (

BF_3

) acts as a Lewis acid because it accepts an electron pair from ammonia (

NH_3

).

Boron trifluoride (

BF_3

) has a central boron atom surrounded by six valence electrons, leaving an empty orbital. In the reaction, it accepts an unshared electron pair from nitrogen in ammonia (

NH_3

) to form a dative covalent bond. By definition, an electron-pair acceptor is a Lewis acid.

Step-by-Step Solution

1

Analyze the electronic structure of the reactants

Boron in

BF_3

has 6 valence electrons (an incomplete octet) and an empty p-orbital, whereas nitrogen in

NH_3

has a lone pair of non-bonding electrons.

Determining electron pair availability is necessary to apply the Lewis acid-base definition.

2

Identify the type of bond formed during the reaction

Nitrogen donates its lone pair into the empty orbital of boron to form a coordinate (dative) covalent bond (

F_3B:NH_3

).

According to the Lewis concept, an electron-pair acceptor is an acid and an electron-pair donor is a base.

3

Evaluate the applicable acid-base theory

Because no proton (

H^+

) transfer occurs and no aqueous

H^+

ions are produced, neither Brønsted-Lowry nor Arrhenius definitions apply, making it strictly a Lewis acid-base reaction.

Lewis theory extends acid-base chemistry to reactions occurring without hydrogen or solvent participation.

Key Concept

Lewis Theory of Acids and Bases

Estimated Time:1m 0s

Question 6793Question →

A large-scale footwear manufacturer in Nigeria decides to bypass wholesale trade and sell its goods directly to independent retail chain outlets. What is the primary operational impact of this decision on the manufacturer?

The manufacturer must absorb the warehousing, inventory financing, and risk-bearing functions previously handled by wholesalers.

The total cost of storage and bulk transportation shifts completely to the final consumer.

The manufacturer completely eliminates all auxiliary commercial functions associated with distribution.

The manufacturer is legally required to issue a credit note for all transport and delivery charges incurred by retailers.

Show answer & explanation

Answer: The manufacturer must absorb the warehousing, inventory financing, and risk-bearing functions previously handled by wholesalers.

Answer

The manufacturer must absorb the warehousing, inventory financing, and risk-bearing functions previously handled by wholesalers.

When a producer bypasses the wholesaler to sell directly to retailers, the essential distribution functions of the wholesaler—such as holding bulk storage, extending credit terms, and absorbing risk of loss or demand fluctuations—do not disappear. Instead, the manufacturer must allocate capital and operational capacity to perform these functions directly.

Step-by-Step Solution

1

Identify the change in the distribution channel structure.

The channel changes from Producer → Wholesaler → Retailer → Consumer to Producer → Retailer → Consumer.

The wholesale stage is bypassed.

2

Analyze the core functions performed by the eliminated middleman (wholesaler).

Wholesalers break bulk, store goods, finance manufacturers through prompt payment, finance retailers through credit, and bear risk.

Middlemen can be eliminated, but their essential distribution functions cannot be eliminated.

3

Determine who absorbs those functions when the wholesaler is removed.

The manufacturer must take over bulk storage, credit extension, and risk management.

Retailers buy in small quantities and cannot store large factory-level stock.

Key Concept

Impact of Eliminating Middlemen in Distribution Channels

Estimated Time:1m 15s

Question 6794Question →

Match each chemical species on the left with its correct molecular shape and central atom hybridization state on the right based on Valence Shell Electron Pair Repulsion (VSEPR) theory.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Chlorine trifluoride (

ClF_3

) matches T-shaped geometry with

sp^3d

hybridization; Xenon tetrafluoride (

XeF_4

) matches Square planar geometry with

sp^3d^2

hybridization; Boron trifluoride (

BF_3

) matches Trigonal planar geometry with

sp^2

hybridization; Triiodide ion (

I_3^-

) matches Linear geometry with

sp^3d

hybridization.

Each species is correctly paired by evaluating its total steric number (sum of sigma bonds and lone pairs) on the central atom to establish hybridization, then removing lone pair domains to find the molecular geometry. Chlorine trifluoride (

ClF_3

) has a steric number of 5 (

sp^3d

) with 2 lone pairs giving a T-shape. Xenon tetrafluoride (

XeF_4

) has a steric number of 6 (

sp^3d^2

) with 2 lone pairs giving a square planar shape. Boron trifluoride (

BF_3

) has a steric number of 3 (

sp^2

) with 0 lone pairs giving a trigonal planar shape. The triiodide ion (

I_3^-

) has a steric number of 5 (

sp^3d

) with 3 lone pairs in equatorial positions giving a linear shape.

Step-by-Step Solution

1

Determine the valence electron count and steric number for each central atom.

For

ClF_3

, steric number is

3 \text{ bonding} + 2 \text{ lone pairs} = 5

. For

XeF_4

, steric number is

4 \text{ bonding} + 2 \text{ lone pairs} = 6

. For

BF_3

, steric number is

3 \text{ bonding} + 0 \text{ lone pairs} = 3

. For

I_3^-

, steric number is

2 \text{ bonding} + 3 \text{ lone pairs} = 5

.

Steric number dictates the electron-pair geometry and the hybridization state of the central atom.

2

Assign the hybridization state based on the steric number.

Steric number 3 gives

sp^2

; steric number 5 gives

sp^3d

; steric number 6 gives

sp^3d^2

.

The number of hybridized orbitals equals the steric number of electron domains.

3

Determine molecular shape by accounting for lone pair positions under VSEPR principles.

ClF_3

(5 domains, 2 equatorial lone pairs) is T-shaped;

XeF_4

(6 domains, 2 axial lone pairs) is square planar;

BF_3

(3 domains, 0 lone pairs) is trigonal planar;

I_3^-

(5 domains, 3 equatorial lone pairs) is linear.

Lone pairs occupy positions that minimize electron repulsion (equatorial in trigonal bipyramidal, axial in octahedral).

Key Concept

VSEPR Theory and Central Atom Hybridization

Question 6795Question →

According to the kinetic theory of matter, the average kinetic energy of the molecules of any gas is directly proportional to its absolute temperature, independent of the mass or identity of the gas.

True

False

Show answer & explanation

Answer: True

Answer

The statement is True.

The postulates of kinetic theory define absolute temperature as a measure of the average kinetic energy of the constituent particles. Regardless of the identity, density, or molar mass of the gas, equal temperatures correspond to equal average kinetic energies.

Step-by-Step Solution

1

Recall the fundamental postulate of the kinetic molecular theory relating heat and motion.

The average kinetic energy of gas particles is directly proportional to the absolute temperature (

T

) measured in Kelvin.

Temperature measures the thermal motion of particles.

2

Examine the mathematical relationship for average kinetic energy.

\bar{E}_k = \frac{3}{2} k_B T

, where

k_B

is Boltzmann's constant and

T

is absolute temperature.

This shows that average kinetic energy depends solely on temperature.

3

Evaluate the impact of gas identity and molecular mass.

Different gases at the same temperature have different average speeds (

v_{rms} = \sqrt{\frac{3RT}{M}}

), but their average kinetic energy remains identical.

Higher mass compensates for lower speed in the formula

E_k = \frac{1}{2}m v^2

.

Key Concept

Direct proportionality between absolute temperature and average kinetic energy of gas particles

Question 6796Question →

An electric circuit consists of a voltage source with an electromotive force (e.m.f.) of $6.0\text{ V}$ and an internal resistance of $1.0\text{ }\Omega$ connected across two identical $6.0\text{ }\Omega$ resistors arranged in parallel. If an ammeter of negligible resistance is connected in series with the voltage source, what current will be displayed on the ammeter?

1.5\text{ A}

2.0\text{ A}

0.75\text{ A}

0.46\text{ A}

Show answer & explanation

Answer: $1.5\text{ A}$

Answer

The ammeter will record a total main circuit current of

1.5\text{ A}

.

The correct response demonstrates proper circuit reduction. First, combining the two

6.0\text{ }\Omega

parallel resistors gives an equivalent resistance of

3.0\text{ }\Omega

. Second, adding the

1.0\text{ }\Omega

internal resistance yields a total resistance of

4.0\text{ }\Omega

. Applying Ohm's law (

I = \frac{E}{R+r}

) gives

I = \frac{6.0\text{ V}}{4.0\text{ }\Omega} = 1.5\text{ A}

, which is the total current measured by an ammeter placed in the main circuit.

Step-by-Step Solution

1

Calculate the equivalent external resistance (

R_p

) of the two parallel resistors.

R_p = \frac{6.0 \times 6.0}{6.0 + 6.0} = \frac{36.0}{12.0} = 3.0\text{ }\Omega

Resistors in parallel combine according to

\frac{1}{R_p} = \frac{1}{R_1} + \frac{1}{R_2}

.

2

Determine the total resistance (

R_{\text{total}}

) of the complete circuit, including internal resistance.

R_{\text{total}} = R_p + r = 3.0\text{ }\Omega + 1.0\text{ }\Omega = 4.0\text{ }\Omega

Internal resistance acts in series with the equivalent external load resistance.

3

Apply Ohm's law for a complete circuit to find the total current (

I

).

I = \frac{E}{R_{\text{total}}} = \frac{6.0\text{ V}}{4.0\text{ }\Omega} = 1.5\text{ A}

The total current supplied by the source equals the electromotive force divided by the total circuit resistance.

Key Concept

Terminal Circuit Current with Internal Resistance and Parallel Resistor Combinations

Question 6797Question →

Match each insurance risk management concept in Column A with its corresponding operational description in Column B.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Reinsurance matches with the transfer of an insurer's risk to another insurer; Co-insurance matches with the joint coverage of a single risk by multiple primary insurers directly with the policyholder; Underwriting matches with the process of evaluating risk details and setting premium rates.

Reinsurance correctly pairs with transferring part of an accepted risk exposure from one insurer to another. Co-insurance correctly pairs with two or more insurers jointly sharing a risk directly with the policyholder. Underwriting correctly pairs with the process of assessing risk hazards to determine acceptance and premium rates.

Step-by-Step Solution

1

Analyze the operational scope of Reinsurance.

Identify that reinsurance is an insurer-to-insurer contract where an existing risk is partially ceded to reduce exposure.

Reinsurance does not involve direct contractual interaction between the reinsurer and the original policyholder.

2

Analyze the operational scope of Co-insurance.

Identify that co-insurance is a joint effort among two or more primary insurers to share risk coverage directly with the policyholder.

All participating co-insurers share fixed percentages of risk and maintain direct relationships with the insured.

3

Analyze the operational scope of Underwriting.

Identify that underwriting is the risk selection and pricing process.

The underwriter inspects proposal details to decide policy terms and premium charges before accepting the risk.

Key Concept

Reinsurance, Co-insurance, and Underwriting Concepts

Estimated Time:1m 0s

Question 6798Question →

Complete the following statement regarding acid-base behavior according to the Brønsted-Lowry theory.

Fill in the blanks below

In the reversible reaction

HSO_4^- + H_2O \rightleftharpoons SO_4^{2-} + H_3O^+

, the species that acts as the conjugate base of hydrogen sulfate ion (

HSO_4^-

) is the ion.

Show answer & explanation

Answer

sulfate (or tetraoxosulfate(VI),

SO_4^{2-}

)

Under the Brønsted-Lowry definition, an acid is a proton donor and its conjugate base is the species remaining after the loss of that proton. When the hydrogen sulfate ion (

HSO_4^-

) donates a proton (

H^+

), it forms the sulfate ion (

SO_4^{2-}

), making sulfate the conjugate base.

Step-by-Step Solution

1

Identify the Brønsted-Lowry acid in the forward reaction.

The hydrogen sulfate ion (

HSO_4^-

) acts as an acid by donating a proton (

H^+

).

By definition, a Brønsted-Lowry acid is a proton donor.

2

Determine the remaining species after proton donation.

Removing

H^+

from

HSO_4^-

yields

SO_4^{2-}

.

When an acid loses a single proton, the remaining chemical species formed is its conjugate base.

Key Concept

Brønsted-Lowry Conjugate Acid-Base Pairs

Question 6799Question →

In home trade, buyers and sellers issue specialized financial and accounting records to facilitate order processing, delivery, and correction of transaction errors. Match each document issued during a trading transaction on the left with its corresponding purpose on the right.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Advice Note matches informing the buyer in advance of goods dispatch; Consignment Note matches third-party freight delivery instructions and proof of carriage; Statement of Account matches summarizing transactions and balance due over a period; Debit Note matches notifying the buyer of an undercharge on an invoice.

Each home trade commercial document fulfills a precise function: Advice Notes give advance notice of dispatch; Consignment Notes handle third-party freight details; Statements of Account summarize periodic credit transactions; and Debit Notes rectify undercharged billing.

Step-by-Step Solution

1

Identify the document used to give advance notice of goods dispatch.

Advice Note matches informing the buyer that goods have been dispatched.

An advice note alerts the buyer to prepare for receiving the incoming shipment.

2

Identify the document required when using an independent transportation carrier.

Consignment Note matches third-party freight instructions and receipt proof.

A consignment note details freight terms and acts as contract of carriage between sender, carrier, and consignee.

3

Determine the periodic document summarizing trade activities between buyer and seller.

Statement of Account matches the summary of all transactions and outstanding balances.

Sellers issue periodic statements of account to request settlement for accumulated purchases over a period.

4

Determine the corrective document used to rectify an undercharge.

Debit Note matches notifying the buyer of an undercharge on an invoice.

A debit note is issued when an invoice was underpriced or omitted items, effectively debiting the customer's account further.

Key Concept

Functions of Commercial Documents in Home Trade

Question 6800Question →

Match each sparingly soluble salt with its correct solubility product ( $K_{sp}$ ) expression, where $s$ represents the molar solubility of the salt in $\text{mol dm}^{-3}$ .

Click a left item, then click its matching right item

Show answer & explanation

Answer

Calcium sulfate matches

K_{sp} = s^2

; Silver chromate matches

K_{sp} = 4s^3

; Aluminium hydroxide matches

K_{sp} = 27s^4

; Calcium phosphate matches

K_{sp} = 108s^5

.

Each salt dissociates according to its stoichiometry

A_x B_y \rightleftharpoons x A^{y+} + y B^{x-}

, giving

K_{sp} = x^x y^y s^{x+y}

. Calcium sulfate (a 1:1 salt) gives

s^2

; silver chromate (a 2:1 salt) gives

4s^3

; aluminium hydroxide (a 1:3 salt) gives

27s^4

; and calcium phosphate (a 3:2 salt) gives

108s^5

.

Step-by-Step Solution

1

Write the balanced dissolution equilibrium for a generic sparingly soluble salt

A_x B_y

.

A_x B_y(s) \rightleftharpoons x A^{y+}(aq) + y B^{x-}(aq)

This establishes the stoichiometry of the dissolved ions in solution.

2

Express the concentration of each constituent ion in terms of molar solubility

s

.

[A^{y+}] = xs

and

[B^{x-}] = ys

Molar solubility

s

represents the moles of salt dissolved per

\text{dm}^3

of saturated solution.

3

Substitute the ionic concentrations into the solubility product expression

K_{sp} = [A^{y+}]^x [B^{x-}]^y

.

K_{sp} = (xs)^x (ys)^y = x^x y^y s^{(x+y)}

This yields the general mathematical relationship between

K_{sp}

and

s

for any ionic solid.

4

Apply the general formula to each specific salt based on its stoichiometric coefficients

x

and

y

.

For

\text{CaSO}_4

(

1:1

),

K_{sp} = 1^1 \cdot 1^1 \cdot s^{1+1} = s^2

. For

\text{Ag}_2\text{CrO}_4

(

2:1

),

K_{sp} = 2^2 \cdot 1^1 \cdot s^{2+1} = 4s^3

. For

\text{Al(OH)}_3

(

1:3

),

K_{sp} = 1^1 \cdot 3^3 \cdot s^{1+3} = 27s^4

. For

\text{Ca}_3(\text{PO}_4)_2

(

3:2

),

K_{sp} = 3^3 \cdot 2^2 \cdot s^{3+2} = 108s^5

.

Matching each salt with its stoichiometric coefficients produces the correct mathematical relationship.

Key Concept

Derivation of Solubility Product (

K_{sp}

) expressions from stoichiometric dissolution equilibria.

Answer

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