Multiple Choice
During combustion analysis, how does matter change when a hydrocarbon burns in oxygen, and why does this occur?
81
views
3. Chemical Reactions
Combustion Analysis
Multiple Choice
How many molecules of water are produced by the complete combustion of 3.00 g of methane (CH_4)?
A
6.02 × 10^{22} molecules
B
1.13 × 10^{23} molecules
C
4.52 × 10^{23} molecules
D
2.26 × 10^{23} molecules
Verified step by step guidance1
Write the balanced chemical equation for the complete combustion of methane (CH_4): \(\mathrm{CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O}\).
Calculate the number of moles of methane in 3.00 g using its molar mass. The molar mass of methane (CH_4) is calculated as \(12.01 + 4 \times 1.008\) g/mol. Use the formula: \(\text{moles of CH}_4 = \frac{\text{mass of CH}_4}{\text{molar mass of CH}_4}\).
Use the mole ratio from the balanced equation to find the moles of water produced. According to the equation, 1 mole of CH_4 produces 2 moles of H_2O, so multiply the moles of CH_4 by 2.
Convert the moles of water to molecules using Avogadro's number, \(6.022 \times 10^{23}\) molecules/mol. Use the formula: \(\text{molecules of H}_2\text{O} = \text{moles of H}_2\text{O} \times 6.022 \times 10^{23}\).
Compare your calculated number of water molecules to the given options to identify the correct answer.
Related Videos
Related Practice
