Question

Using your understanding of the specific heat capacity, how much energy in Joules will it take to increase 25g of water (specific heat capacity =4.2J/g•°C) from 30°C to 33°C?

Answer 1

The equation that relates temperature change and heat is as follows:

$Q=mc\Delta T$

Where Q is the heat, m is the mass, c is the specific heat capacity and ΔT is the change in temperature (final temperature minus initial temperature.

$\Delta T=T_f-T_i$

The specific heat capacity is given:

$c=4.2J/(g\degree C)$

And the mass is also given:

$m=25g$

And the initial temperature is 30°C and the final is 33°C, so:

$\Delta T=33\degree C-30\degree C=3\degree C$

So, putting altogether, we have:

$\begin{gathered} Q=25g\cdot4.2J/(g\degree C)\cdot3\degree C \\ Q=25\cdot4.2\cdot3\; J \\ Q=315\; J \end{gathered}$

So, we need 315 J of energy.