Energy of chemical reaction question?

Question

An oxy-acetylene welding torch uses ethene (acetylene) at the rate of 500ml per minute, measured at STP. The reaction is 2C2H2 + 502---> 4CO2+ 2H2O ; H= -2599kj mol-1

1. What is the heat of combustion of ethyne in kj mol-1 and kj g-1

2. Calculate the rate of enery production by the torch in kj per minute.

Answer 1

@ 2C2H2 + 502---> 4CO2+ 2H2O ; H= -2599kj mol-1

1. What is the heat of combustion of ethyne in kj mol-1 :

they gave that answer:  H= -2599kj mol-1

and kj g-1 , using the molar mass of C2H2 of 26.0373 g/mol:

-2599kJ / 26.0373 =

your answer Is : 99.82 kj/ gram

=============================

2. Calculate the rate of enery production by the torch in kj per minute.

@ stp, the molar volume of gases is 22,400 ml,... so

500 ml/min @ 22,400ml / mole = 0.02232 moles per minute

( 0.02232 moles per minute) times  (2599kj/mole) = 58.01 kJ/minute

assuming that they intended the 500ml to have 3 sig figs,

your answer is 58.0kJ/min