All practice questions

A saturated solution of potassium chloride ($\text{KCl}$) contains $14.9\text{ g}$ of the salt dissolved in $100\text{ g}$ of water at $25^\circ\text{C}$. What is the solubility of potassium chloride in $\text{mol/dm}^3$ at this temperature?

(Take density of water = $1.0\text{ g/cm}^3$, relative atomic masses: $\text{K} = 39$, $\text{Cl} = 35.5$)

Read the poetic excerpt below:

When storm clouds gather on the northern peak,
And ancient winds awaken from their sleep,
The mountain pines begin to bend and speak,
While valleys hold their breath in shadows deep.

Yet in the quiet heart of yonder grove,
A single candle burns against the night,
To whisper solace born of steadfast love,
And shield the weary traveler with its light.

Which of the following best describes the stanzaic structure and rhyme scheme of the excerpt?

A commercial firm based in Aba purchases crude palm oil in bulk from local producers in Imo State and resells it to soap manufacturing companies in Kaduna State. Which classification of trade best describes this firm's primary activity?

A sample of oxygen gas is collected over water at $27^\circ\text{C}$ and a total pressure of $755\text{ mmHg}$. If the saturated vapor pressure of water at $27^\circ\text{C}$ is $25\text{ mmHg}$, what is the partial pressure of the dry oxygen gas in $\text{mmHg}$?

A public limited company is legally permitted to commence business operations and exercise its borrowing powers immediately upon receiving its Certificate of Incorporation.

Match each atmospheric pollutant listed on the left with its primary health or environmental impact listed on the right.

A block and tackle system consisting of $5$ pulleys is used to raise a load of $200\text{ N}$ through a vertical height of $4\text{ m}$. If the efficiency of the system is $80\%$, what is the work done against friction, in joules, during the lifting process?

A longitudinal mechanical wave propagates through a gas at a speed of $340\text{ m/s}$. If a particle in the gas completes $50$ full oscillations in $0.10\text{ s}$, what is the distance between a compression and the immediate next rarefaction?

Match each chemical species containing a central transition metal or halogen atom with its corresponding systematic IUPAC name and central element oxidation number.

A sample of pure ammonium trioxocarbonate(IV), $(\text{NH}_4)_2\text{CO}_3$, is determined to contain $3.6 \times 10^{24}$ hydrogen atoms. What is the total mass of oxygen present in this sample?

[Relative atomic masses: $\text{H} = 1$, $\text{C} = 12$, $\text{N} = 14$, $\text{O} = 16$; Avogadro's constant $N_A = 6.0 \times 10^{23} \text{ mol}^{-1}$]

Match each dramatic character type on the left with its corresponding defining feature or dramatic function on the right.

Match each prose narrative scenario to the central theme it predominantly illustrates in literary prose analysis.

Consider the structural arrangement of the eight-line passage below:

Upon the ancient shore the billows break,
And scatter foam across the darkened sand;
The lonely traveller steps upon the land,
Uncertain of the journey he must take.
No distant beacon shines for safety's sake,
Nor guidance comes from any friendly hand;
Yet firm in purpose does he proudly stand,
Determined that his courage will not shake.

Which of the following best describes the stanzaic structure and rhyme scheme of this passage?

A capacitor of capacitance $5\text{ }\mu\text{F}$ is charged to a potential difference of $200\text{ V}$ and then disconnected from the power supply. If it is subsequently connected in parallel across an uncharged capacitor of capacitance $15\text{ }\mu\text{F}$, what is the final common potential difference across the combination in volts?

An enterprise presents the following financial balances at the end of its trading year:

- Premises and Machinery: $\text{₦}1,850,000$
- Stock (Inventory): $\text{₦}410,000$
- Trade Debtors: $\text{₦}240,000$
- Cash at Bank: $\text{₦}150,000$
- Trade Creditors: $\text{₦}270,000$
- Accrued Expenses: $\text{₦}130,000$
- Long-term Loan: $\text{₦}600,000$

What is the Capital Employed of the enterprise in Naira ($\text{₦}$)?

A laboratory technician needs to recover pure hydrated copper(II) tetraoxosulfate(VI) crystals ($\text{CuSO}_4\cdot5\text{H}_2\text{O}$) from an aqueous suspension containing insoluble copper(II) oxide residue. Which of the following procedures correctly describes the optimal method to obtain the dry, hydrated crystals?

Match each chemical substance with its characteristic atmospheric behavior or hydration property when exposed to ambient laboratory air or heat:

A machine with a velocity ratio of $6$ is used to raise a load of $540\text{ N}$ by applying an effort of $120\text{ N}$. What is the efficiency of the machine?

What is the percentage by mass of water of crystallization in copper(II) tetraoxosulfate(VI) pentahydrate ($\text{CuSO}_4 \cdot 5\text{H}_2\text{O}$)? $[\text{Cu} = 64, \text{S} = 32, \text{O} = 16, \text{H} = 1]$

Two weak monobasic acids, $\text{HX}$ ($K_a = 1.0 \times 10^{-5}\text{ mol dm}^{-3}$) and $\text{HY}$ ($K_a = 4.0 \times 10^{-5}\text{ mol dm}^{-3}$), are prepared as aqueous solutions. Solution X contains $0.40\text{ mol dm}^{-3}$ of $\text{HX}$, whereas Solution Y contains $0.10\text{ mol dm}^{-3}$ of $\text{HY}$. Based on Ostwald's dilution law and the principles of acid ionization, which of the following statements correctly compares the two solutions?