Question

How much energy is released when 73.0 g of ethylene reacts? Be sure your answer has the correct number of significant figures.

kcal released

Answers

GPT 3.5
The molar mass of ethylene (C2H4) is 28.05 g/mol.

First, let's calculate the moles of ethylene in 73.0 g:

73.0 g / 28.05 g/mol = 2.60 mol

The balanced chemical equation for the combustion of ethylene is:

C2H4 + 3 O2 -> 2 CO2 + 2 H2O

From this equation, we see that 1 mole of C2H4 releases 141.8 kcal of energy.

So, for 2.60 moles of C2H4, the energy released would be:

2.60 mol * 141.8 kcal/mol = 369.08 kcal

Therefore, when 73.0 g of ethylene reacts, 369.08 kcal of energy is released. This value should be rounded to three significant figures, so the final answer is 369 kcal.