Question

When 13.0 g of acetylene, C2H2, undergoes complete combustion, 65.5 kJ of heat are released.
a) How much energy is released when one mole of acetylene is burned?
b) Write a balanced chemical equation for the reaction and include the heat value in the equation.

Answer 1

Mass of one mol C2H2
= 2*12 + 2 = 26 grams/mol
(26/12) * 65.5 =131 kJ

xC2H2 + (.5 x+2x)O2 ===> 2xCO2 + x H2O
so try x = 2
2 C2H2 + 5 O2 ===> 4 CO2 + 2 H2O that works :)

Answer 2

typo
26/13 I mean