# Thermochemistry please

posted by
**Jina**
.

I really need help on this problem...

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

Hydrocarbon Formula Delta H (kj/mol)

1,3-Butadiene C4H6(g) 111.9

a) calculate the fuel value in kJ/g for this compound and determine the percentage of hydrogen by mass.

I've tried it for hours yet I can't figure out how to do this.

Please help thank you@!!

You have kJoules/mol. How many grams of this compound are in one mole? Divide your given number by the grams in a mole to get kJ/g.

Percentage of H?

6(atomic mass H)/molmassC4H6 * 100

Here is the problem-

Calculate the total enery change when warming 5.00g of ice at -15 degrees celcius to liquid water at 25 degrees celcius.

could i get a step by step solution and answer to this problem??? What is the thermal energy change as 175.og of water drops from 75.00 degrees celcius to 15.50 degrees celcius? help?