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:

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.

the answer is true.

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prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.