Explanation:

When an exothermic reaction occurs in a bomb calorimeter, it means that heat is being released by the reaction. In this case, the temperature of the water bath in the bomb calorimeter will increase. This can be explained by the principles of thermodynamics.

Calorimetry:
Calorimetry is the science of measuring the heat of chemical reactions or physical changes. A bomb calorimeter is a device used to measure the heat of combustion of a substance. It consists of a sealed container (bomb) where the reaction takes place, surrounded by a water bath.

Exothermic Reaction:
An exothermic reaction is a chemical reaction that releases heat energy. In this type of reaction, the energy of the reactants is higher than the energy of the products, resulting in the release of excess energy in the form of heat.

Bomb Calorimeter:
In a bomb calorimeter, the reaction takes place inside the bomb, which is surrounded by a water bath. The bomb is sealed to prevent any heat exchange with the surroundings. As the reaction occurs, the heat produced is transferred to the water bath.

Temperature of the Water Bath:
When an exothermic reaction occurs in the bomb calorimeter, the heat released by the reaction is transferred to the water bath. This leads to an increase in the temperature of the water bath. The water molecules gain kinetic energy from the heat, causing them to move faster and increase in temperature.

Since the bomb is sealed, the heat released by the reaction cannot escape to the surroundings. Therefore, the water bath acts as a heat sink, absorbing the released heat and increasing in temperature.

Conclusion:
In conclusion, when an exothermic reaction occurs in a bomb calorimeter, the temperature of the water bath increases. This is because the heat released by the reaction is transferred to the water bath, causing an increase in its temperature.