How much energy is released when the following amounts of propane are burnt? i) 0.2 mol ii) 4 mol iii) 33 grams

i) -444.0 KJ/mol.

ii) -8880 KJ/mol.

iii) -1660.56 KJ/mol.

Explanation:

To solve this problem, we should mention the reported value of burning one mole of propane (ΔH°combustion = -2220 KJ/mol).

C₃H₈ + O₂ → 3CO₂ + 4H₂O

i) The energy released from burning 0.2 mol:

Using cross multiplication:

1.0 mol → -2220 KJ/mol

0.2 mol → ??? KJ/mol

The energy released = (-2220 KJ/mol x 0.2 mol) / (1.0 mol) = -444.0 KJ/mol.

ii) The energy released from burning 4.0 mol:

Using cross multiplication:

1.0 mol → -2220 KJ/mol

4.0 mol → ??? KJ/mol

The energy released = (-2220 KJ/mol x 4.0 mol) / (1.0 mol) = -8880 KJ/mol.

iii) The energy released from burning 33.0 g of propane:

Firstly, we should convert the number of grams to moles.

n = mass/molar mass = (33.0) / (44.1 mol/g) = 0.748 mol.

Using cross multiplication:

1.0 mol → -2220 KJ/mol

0.748 mol → ??? KJ/mol

The energy released = (-2220 KJ/mol x 0.748 mol) / (1.0 mol) = -1660.56 KJ/mol.

Since there is the same amount of agn03 in both silver chloride and silver nitrate they produce the same amount of moles. therefore silver chloride produces the same amount of silver nitrate, so your answer is 15.0 moles of silver nitrate. i hope this !

And a) oxygen i believe