Question

How can the enthalpy change be determined for a reaction in an aqueous solution? By mixing the reactants in a calorimeter and measuring the temperature change By knowing the specific heat of the reactants By knowing the mass of the reactants The enthalpy change for this type of reaction cannot be determined.

Answer 1

Answer:

The enthalpy change of a reaction can be determined by mixing the reactants in a calorimeter and measuring the temperature change.

Explanation:

When mixing two solutions with a certain amount of solutes that can react, a change in the enthalpy of the system occurs. This energy change at constant pressure can be determined using a calorimeter. This device contains the solutions and practically does not absorb any heat from it. However, the heat absorbed by the calorimeter should be determined to consider it when measuring precise enthalpy parameters.

Once the reaction takes place inside the calorimeter, a change in temperature is evident because the reaction can gain or release energy that is absorbed or gained by the aqueous solution. By Measuring the initial and final temperature of the solution and using as an approach the specific heat similar to water (valid for diluted solutions) we can find the enthalpy of reaction as follows:

$\Delta H_{rxn} = - (q_{calorimeter} +q_{solution})$

$q_{solution} = m_{solution} * S_{H-water}* \Delta T$  

Answer 2

I think the correct answer would be the second option. Enthalpy change can be determine for a reaction in an aqueous solution by knowing the specific heat of the reactants. You can use the equation H = mC(deltaT) where m is the mass, C is the specific heat and (deltaT) is the change in temperature.