Calories (cal) Definition - Intro to Chemistry Key Term

Definition

A calorie (cal) is a unit of energy. In chemistry, it is commonly used to quantify the amount of energy transferred in reactions.

1 calorie is defined as the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius.
The relationship between calories and joules is: $1 \, \text{cal} = 4.184 \, \text{J}$.
Calories are often used in thermochemistry to measure heat changes in chemical reactions.
Nutritional calories (Calories with an uppercase C) are equivalent to kilocalories (kcal), where $1 \, \text{Cal} = 1000 \, \text{cal}$.
In calorimetry, the specific heat capacity of a substance is used alongside calories to determine energy changes.

Joule (J): A derived unit of energy in the International System of Units. One joule is equal to $1 \, \text{kg} \cdot \text{m}^2 / \text{s}^2$.

The amount of heat per unit mass required to raise the temperature by one degree Celsius.

The science of measuring the heat change associated with a chemical reaction or physical process.