Question

How much energy is needed to change the temperature of 50.0 g of water by 15.0oc?

Answer 1

The amount of energy needed to increase the temperature of a substance by $\Delta T$ is given by:
$Q=m C_s \Delta T$
where
m is the mass of the substance
Cs is the specific heat capacity of the substance
$\Delta T$ is the increase in temperature

In our problem, m=50.0 g, $C_s = 4.18 J/g ^{\circ}C$ (specific heat capacity of water) and $\Delta T=15.0 ^{\circ}C$, therefore the amount of energy needed is
$Q=mC_s \Delta T=(50.0 g)(4.18 J/g^{\circ}C)(15.0^{\circ}C)=3135 J$