# What is the relationship between heat and calorimetry?

Apr 13, 2014

Calorimetry is an experimental method that allows one to calculate the heat change in a chemical process.

calorimeter is just a reaction vessel. It could be a foam cup, a soda can, or a commercially available bomb calorimeter like http://www.parrinst.com/products/oxygen-bomb-calorimeters/1341-plain-jacket-bomb-calorimeter/.

Basically, you have a certain amount of water surrounding a reaction. You measure the temperature change in that water, and you use that to calculate the heat gained or released during a process. That equation usually takes a form:

$- {q}_{r x n} = {q}_{c a l} + {q}_{w a t e r}$

Where q represents the heat change in the reaction, the calorimeter and the water. Since you are only measuring temperature, you will need to calculate the heat using it.

The change in heat of the calorimeter is given by:
${q}_{c a l} = C \Delta T$ where C is the heat capacity of the calorimeter.

The change in heat of the water is given by:
${q}_{w a t e r} = {c}_{p} m \Delta T$ where ${c}_{p}$ is the specific heat of water, which is 4.184 J/gC, m is the mass of water in the calorimeter in grams, and delta T is the change in temperature.

The video discusses how to solve a sample calorimetry calculation.

Video from: Noel Pauller

See here for more sample calculations:
http://www.chem.ufl.edu/~itl/2045/lectures/lec_9.html

Another video on calorimetry: