Stoichiometry And Mole Ratio

Question

In the combustion reaction $\text{C}_3\text{H}_8 + 5\text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}$, how many moles of oxygen are required to completely burn 2.2 g of propane ($\text{C}_3\text{H}_8$)? (Molar mass of $\text{C}_3\text{H}_8 = 44$ g/mol)

RankGuru · Accepted Answer

Stoichiometry uses the balanced chemical equation to relate moles of reactants and products. The balanced equation shows that 1 mol of propane requires 5 mol of oxygen. First, find the moles of propane: $n_{\text{C}_3\text{H}_8} = 2.2/44 = 0.05$ mol. From the mole ratio, moles of $\text{O}_2$ required $= 0.05 \times 5 = 0.25$ mol. Option 0.05 mol is the number of moles of propane itself, not oxygen — the mole ratio has not been applied. Option 0.50 mol is double the correct value and would correspond to 10 mol of $\text{O}_2$ per mol of propane, not 5. Option 1.00 mol is 4 times the correct answer and arises from an incorrect mole ratio of 20:1 instead of 5:1. This is a direct NCERT stoichiometry calculation requiring mole ratio from a balanced equation. Plausibility check: 0.25 mol of $\text{O}_2$ has mass $0.25 \times 32 = 8$ g, which is reasonable for burning a small amount of propane.

Stoichiometry And Mole Ratio

Select the correct option:

🔒 Solution Hidden from View

More some basic concepts in chemistry Practice Questions

Upon complete combustion of 0.45 g of an organic compound containing only C, H, and O, 0.66 g of (...

In the balanced equation for the reaction of aluminium with dilute sulfuric acid to produce aluminiu...

100 mL of 0.5 M (\text{BaCl}_2) solution is mixed with 200 mL of 0.3 M (\text{Na}_2\text{SO}_4) ...

A sample of drinking water was found to contain 0.032 g of fluoride ions dissolved in 16 kg of water...

Consider the reaction: (\text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2)....

A 250 mL solution contains 4.9 g of sulfuric acid ((\text{H}_2\text{SO}_4)). What is the normality...

The average atomic mass of chlorine is 35.5 u. Given that chlorine exists as (^{35}\text{Cl}) (ato...

A hydrocarbon contains 92.3% carbon by mass and has a molar mass of 78 g/mol. What is its molecular ...

What mass of sodium hydroxide (NaOH) must be dissolved in 500 mL of water to prepare a 0.4 M solutio...

A solution is prepared by dissolving 18 g of glucose ((\text{C}6\text{H}{12}\text{O}_6), molar m...

A compound is formed by elements A and B such that two atoms of A combine with three atoms of B. If ...

Calculate the number of molecules present in 9 g of water ((\text{H}_2\text{O})). ((N_A = 6.022 ...

About This Question

Solution