For a given sample of CH3OH, the enthalpy change on reaction is 17 Kj.

Question

How many grams of hydrogen gas are produced?

Part B: What is the value of the change in heat (the sign is a triangle and H) for the reverse of the previous reaction?

Part C: How many kilojoules of heat are released when 28.0 of CO (g) reacts completely with H2 (g) to form CH3OH (g) at constant pressure?

Answer 1

I am going to assume that this is your reaction:

...    CH3OH (g) --> CO (g)  & H2 (g)

dHf's : -201.2   ----> -110.5  & zero

dH reaction = prod - reactants

dH = - 110.5 - (-201.2)

dH = + 90.7 kJ / mole

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How many moles of hydrogen gas are produced?

17 kJ @ 1 mole H2 / 90.7 kJ  = 0.187 moles of H2 are produced

How many grams of hydrogen gas are produced?

0.187 mol @ 2.02 g / mol = 0.0928 grams

your answer is 0.093 grams of H2

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Part B: What is the value of the change in heat (the sign is a triangle and H) for the reverse of the previous reaction?

your answer is dH = "-"

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Part C: How many kilojoules of heat are released when 28.0 of CO (g) reacts completely with H2 (g) to form CH3OH (g) at constant pressure?

28.0 g CO @ 28.0 g/mol = 1 mole of CO

your answer is: dH = - 90.7 kJ / mole

( the sign was changed since this is the reverse of the reaction in (A)