Calorimetry and Heat Capacity Calculations Cheat Sheet

Key Facts

• Heat transfer for a substance is calculated with $q = mc\Delta T$, where $q$ is heat, $m$ is mass, $c$ is specific heat, and $\Delta T$ is temperature change.
• Temperature change is calculated as $\Delta T = T_{\text{final}} - T_{\text{initial}}$.
• If $\Delta T$ is positive, then $q$ is positive and the substance absorbs heat.
• If $\Delta T$ is negative, then $q$ is negative and the substance releases heat.
• Heat capacity is calculated with $C = \frac{q}{\Delta T}$ and has units such as $\text{J}/^\circ\text{C}$ or $\text{J}/\text{K}$.
• Specific heat is calculated with $c = \frac{q}{m\Delta T}$ and is often measured in $\text{J}/(\text{g}\cdot^\circ\text{C})$.
• In an insulated calorimeter, conservation of energy gives $q_{\text{system}} + q_{\text{surroundings}} = 0$.
• For water in many classroom calorimetry problems, use $c_{\text{water}} = 4.184\,\text{J}/(\text{g}\cdot^\circ\text{C})$.

Vocabulary

Calorimetry

Calorimetry is the measurement of heat transfer during a physical or chemical process.

Heat

Heat is thermal energy transferred between objects because of a temperature difference.

Specific Heat

Specific heat is the amount of energy needed to raise the temperature of $1\,\text{g}$ of a substance by $1^\circ\text{C}$.

Heat Capacity

Heat capacity is the amount of energy needed to raise the temperature of an entire object or sample by $1^\circ\text{C}$.

Temperature Change

Temperature change is the difference between final and initial temperature, calculated as $\Delta T = T_{\text{final}} - T_{\text{initial}}$.

Calorimeter

A calorimeter is a device used to measure heat transfer while reducing heat exchange with the outside environment.