Answer to Question #140221 in General Chemistry for Princess Mariano

Question

Identify whether the following process are endothermic or exothermic. Justify your answer.

1. Burning coal
2. Neutralization between an acid and a base
3. Combustion of gasoline
4. Solid lead(II)chloride (PbCl2) dissolves only in hot water.
5. Heating causes sodium bicarbonate (NaHCO3) to decompose.

Answer 1

1. Burning coal is strictly exothermic as it releases heat energy.

2. Neutralization between an acid and base is exothermic since heat energy is given out.

3.Combustion reactions, such as that of gasoline, are exothermic as they emit heat.

4. Lead Chloride is poorly soluble in cold water. Since it dissolves in hot water, the process is endothermic because it requires heat energy.

5.Decomposition reactions, like that of decomposing NaHCO₃ , are endothermic as they require heating.