Question

If a reaction causes 20.0 ml of water to decrease temperature by 4.72 °C at constant pressure, what would be the change in temperature if 31.5 ml of water were used instead? assume change in enthalpy of the reaction remains the same.

Answer 1

If 20.0 ml of water results in a temperature decrease of 4.72 °C, using 31.5 ml of water with the same change in enthalpy would lead to a proportional decrease in temperature change. The temperature change for 31.5 ml of water can be calculated to be approximately 3.00 °C.

Step-by-step explanation:

When the amount of water used in a chemical reaction is increased from 20.0 ml to 31.5 ml, and the change in enthalpy of the reaction remains the same, the resulting change in temperature will be inversely proportional to the amount of water.

Therefore, if 20.0 ml of water experienced a temperature decrease of 4.72 °C, the temperature change for 31.5 ml of water can be calculated using a ratio, setting up a direct proportion between the volume of water and the temperature change. Since 31.5 ml is 1.575 times more than 20.0 ml, the temperature change for 31.5 ml will be 4.72 °C divided by 1.575, which equals a temperature change of approximately 3.00 °C.