Question

A piece of metal is heated and placed in a foam-cup calorimeter containing 100.0 mL of water at 28.1°C. The water reaches a maximum temperature of 30.3°C. How many joules of heat are released by the metal? Show your work.

Answer 1

The joules of heat released by the metal will be the same that the ones received by the water.

To find the joules that the water received, use the following formula:

`Q=mCp(T2-T1)`

Where Q is the heat released or absorbed, m is the mass, Cp is the specific heat and T2 and T1 are the final and initial temperatures:

The value of Cp for water is 4.18J/g°C, the mass can be found using the density of water which is 1g/mL and T2 and T1 are given:

`m=100.0mL\cdot(1g)/(mL)=100.0g`
`\begin{gathered} Q=100.0g\cdot(4.18J)/(g\degree C)\cdot(30.3\degree C-28.1\degree C) \\ Q=919.6J \end{gathered}`

It means that 919.6 joules of heat are released by the metal.