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Zorluk: Çok zorChemical Reactions and Compounds

Read the chemical reaction scenario below and fill in the blanks with the correct numbers or terms.

Cevap:During the complete combustion of butane (C4H10C_4H_{10}), the hydrocarbon reacts with oxygen gas (O2O_2) to produce carbon dioxide (CO2CO_2) and water vapor (H2OH_2O). When this chemical equation is balanced using the smallest possible whole numbers, the coefficient for oxygen (O2O_2) is 【13】 and the sum of all coefficients in the balanced equation is 【33】. Furthermore, because this process releases net thermal energy to its surroundings, it is thermodynamically classified as an 【exothermic】 reaction.

Cevap

The balanced coefficient for oxygen is 13, the sum of all coefficients is 33, and the reaction is exothermic.
Balancing the complete combustion of butane requires compensating for an odd number of oxygen atoms on the product side by doubling all coefficients. This transforms the intermediate equation (C4H10+6.5O2→4CO2+5H2OC_4H_{10} + 6.5O_2 \rightarrow 4CO_2 + 5H_2O) into the proper whole-number equation (2C4H10+13O2→8CO2+10H2O2C_4H_{10} + 13O_2 \rightarrow 8CO_2 + 10H_2O). The resulting oxygen coefficient is 13, and the total sum of coefficients is 2 + 13 + 8 + 10 = 33. Because the combustion process releases net thermal energy, it is classified as an exothermic reaction.

Adım Adım Çözüm

1
Write the unbalanced skeletal equation for the combustion reaction.
C4H10+O2→CO2+H2OC_4H_{10} + O_2 \rightarrow CO_2 + H_2O
Establishes the chemical formulas for all reactants and products before applying the law of conservation of mass.
2
Balance the carbon (C) and hydrogen (H) atoms first.
C4H10+O2→4CO2+5H2OC_4H_{10} + O_2 \rightarrow 4CO_2 + 5H_2O
There are 4 carbons and 10 hydrogens in a butane molecule, requiring 4 molecules of carbon dioxide and 5 molecules of water to balance those elements.
3
Count the oxygen (O) atoms on the product side to determine the required oxygen on the reactant side.
Products have (4×2)+(5×1)=13(4 \times 2) + (5 \times 1) = 13 oxygen atoms. The reactants need 132\frac{13}{2} O2O_2 molecules.
Oxygen appears in only one reactant but multiple products, making it most efficient to balance last.
4
Multiply the entire equation by 2 to achieve the smallest whole-number coefficients.
2C4H10+13O2→8CO2+10H2O2C_4H_{10} + 13O_2 \rightarrow 8CO_2 + 10H_2O
Standard chemical equations require the lowest possible whole-number coefficients, eliminating the fractional 6.5.
5
Identify the coefficient for oxygen and calculate the total sum of all coefficients.
Oxygen coefficient = 13. Sum = 2+13+8+10=332 + 13 + 8 + 10 = 33.
This directly answers the first two blanks of the prompt based on the fully balanced equation.
6
Classify the reaction type based on its thermal energy transfer.
Exothermic.
Combustion reactions release heat energy into their surroundings, which is the definition of an exothermic process.

Anahtar Kavram

Advanced Stoichiometry and Thermochemistry
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Konular

Chemical Reactions and Compounds

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