Final answer:
Determining the heat capacity of a cup calorimeter is crucial for accurately measuring heat changes during experiments. The formula used is C = q/∆T, with the unit usually being J/°C or cal/°C. Heat capacity is an extensive property, distinct from specific heat, which is an intensive property.
Step-by-step explanation:
Importance of Determining Heat Capacity of a Cup Calorimeter
The determination of the heat capacity of a cup calorimeter is necessary to accurately measure the amount of heat involved in a chemical reaction or a physical process. A calorimeter's heat capacity is the amount of heat required to raise the calorimeter's temperature by one degree Celsius. It is essential to consider this because the calorimeter itself absorbs heat, which can influence the temperature change measured during an experiment.
Formula for Calculating Heat Capacity of a Cup Calorimeter
The heat capacity (C) of a calorimeter can be calculated using the formula q = C∆T, where q is the heat exchanged, and ∆T is the change in temperature. To find C, one must rearrange the formula to C = q /∆T after measuring the amount of heat exchanged and the resultant temperature change when a known amount of heat is added or removed from the calorimeter.
Units of Heat Capacity
The unit of heat capacity for a cup calorimeter is usually expressed in joules per degree Celsius (J/°C) or calories per degree Celsius (cal/°C).
Heat Capacity vs. Specific Heat
It is important to distinguish between heat capacity and specific heat. Heat capacity is an extensive property, meaning it depends on the amount of substance, while specific heat is an intensive property that remains the same regardless of the quantity of the substance. Specifically, heat capacity refers to the total heat required to raise the temperature of an object by 1 degree Celsius, while specific heat refers to the heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius.