Question

Consider the following reaction: 2CH3OH ---> 2CH4+O2 delta H= +252.8kJ
Calculate the amount of heat transferred when 22.0g of CH3OH(g) is decomposed by this reaction at constant pressure. Include units

Answer 1

to solve this,
calculate the no. of moles of methanol. which is = 22g/32g
32g is the molar mass of methanol.
the no. of moles comes out to be. 0.6875

the question says that.

2 moles of methanol gives 252.8kJ of energy at constant pressure.
so, how much energy is given off by 22grams of methanol or we may say 0.6875 moles of methanol.

so, 0.6875 moles will give energy equal to (252.8 * 0.6875)/2 kJ of energy.
which comes out to be 86.9kJ of energy.