I have delta h=-777kj+1atmospheres× delta V. I just dont know how to find delta V from the problem.. Created by terry longie. science-mathematics-en - chemistry-en

At constant pressure, the combustion of 15.0 g of C2H6 (g) releases 777 kJ of heat. What is ΔH for the reactio?

May 2021 2 365 Report

At constant pressure, the combustion of 15.0 g of C2H6 (g) releases 777 kJ of heat. What is ΔH for the reactio?

I have delta h=-777kj+1atmospheres× delta V. I just dont know how to find delta V from the problem.

The reaction is:

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

So you need the heat produced by the complete combustion of 2 moles of C2H6.

(15.0 g C2H6) / (30.06924 g C2H6/mol) = 0.49885 mol C2H6

(777 kJ) / (0.49885 mol) x (2 mol) = 3115 kJ

So:

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O, ΔH = 3115 kJ