Question

If a block of metal is placed in a calorimeter and the water in the calorimeter gets warmer, determine the direction that heat flowed by defining the system and surroundings. Was heat lost or gained by the system? If +3220 J of heat is lost to the water in a calorimeter by an exothermic reaction at constant pressure, what is the enthalpy of the reaction? In two sentences or less, define the term standard heat capacity as it applies to a calorimetry experiment.

Answer 1

Ans :

When the hot block of metal is placed in the calorimeter ,the water of the calorimeter gets warm. This means that the direction of heat is from hot metal to the cold water as metal is the system that releases heat and water is the surrounding that gains heat.

So here system loses heat.

When the heat is lost to the surroundings in an exothermic reaction that means heat is evolved by the system. So the enthalpy of the reaction is -3220 J.

The specific heat capacity of the substance is the amount of heat required by 1 g of substance to raise the temperature by 1^oC.