You have 10g of pentane undergo combustion with 12g of oxygen , how many molecules of CO2 are produced?

Answer 1

Pentane = C₅H₁₂

molar mass = 72.15 g/mol

Write the correctly balanced equation for the combustion of pentane:

C₅H₁₂ + 8O₂ ==> 5CO₂ + 6H₂O ... balanced equation

Determine if C₅H₁₂ or O₂ is limiting:

C₅H₁₂: 10 g C₅H₁₂ x 1 mol C₅H₁₂ / 72.15 g x 5 mol CO2/mol C₅H₁₂ = 0.693 moles CO2 produced

O₂: 12 g O₂ x 1 mol O₂/32 g x 5 mol CO₂/8 mol O₂ = 0.234 mol CO₂ produced (LIMITING)

Determine molecules of CO₂ produced:

Since O₂ is limiting, only 0.234 moles of CO₂ can be produced. Converting this to molecules CO₂ we have..

0.234 moles CO₂ x 6.02x10²³ molecules/mol = 1.4x10²³ molecules of CO₂