Question

Energy change is measured:

CH4(g) + 2 O2 (g) --> CO2 (g) + 2 H2O (l)   ΔH−882.kJ

Is the reaction endothermic or exothermic?

If 22.8g of CH4 react, will any heat be absorbed or relased?

If yes, calculate how much heat will be released or absorbed with correct significant digits.

Answer 1

The given reaction is a combustion reaction which is exothermic.

It is exothermic because the delta H value is negative (heat is released)

2) As the reaction is exothermic , if 22.8 g of methane is reacted , heat is released.

3) From the reaction

CH4(g) + 2O2(g) -----------> CO2(g) +2H2O(l) ; delta H = -882kJ

the heat liberated = 882kJ

That is when one mole of CH4( 16g/mol) is burnt heat given out is 882kJ

if 22.8g of methane is burnt heat released = 22.8gx 882kJ/16g

= 1256.85 kJ