Homework Answers

Given the following thermochemical equations:

1.) 4NH3)+302(g) → 2N₂(g) + 6H₂0 (1) ∆H°-1531 kJ

2.) N₂O(g) + H₂(g) → N₂(g) + H₂O(0) ∆H°-367.4 k]

3.) H₂(0)+02 (0)→ H₂0 (1)

∆H°= -285.9 kJ

Find the value of AH" for the reaction:

2NH3(g) + 3N₂0(g) → 4N₂(g) + 3H₂O(1)

Chlorine trifluoride is a colorless, poisonous, and corrosive gas. It is produced from the reaction between chlorine fluoride and fluorine gas.

CIF(g) + F2 (g) → CLF3 (9)

Determine the ∆H° for the overall reaction based on the three-step thermochemical process below:

1.) 2CLF(g) + O2(g) → Cl₂0(g) + F₂0 (g) ∆°H-167.5 k]

2.) 2C1F3(g) +202(g) → Cl₂0(g) + 3F₂0(g)

∆H° =-341.4 k]

3.) 3F₂0)→2F2 (g) + O2(g)

∆H° = 43.4 kJ

A system absorbs 50J of heat during a transformation. Determine the change in internal energy if 

the system perform, (a) 15J and (b) 65J of work on the surrounding.

Find the ∆E

a) When 175J of work is done on a system that evolves 50J of heat to the surrounding.

b) When a gas absorbs 28kJ of heat and 13kJ of work done on it.