Question

how many calories are needed to raise the temperature of 21.0 g of silver from 22 degrees Celsius to 48 degrees Celcius

Answer 1

Let find the energy, that need to heat silver:

$Q=c\times m\times \Delta T$ ,

where:

$\Delta T=T_{2}-T_{1}=26K, m=21g=21\times10^{-3} kg.$

c is a constant and for silver:

$c=250\dfrac{J}{kg\times K}$

$Q=136.5 J$

We know that:

$1c(calorie)=4.184J(Joule)$

or:

$1J(Joule)=0.239c(calorie)$

So to raise the temperature of silver we need:

$0.239\times 136.5=32.6235 c(calories)$