Question

Calculate the energy to heat two cubes (gold and aluminum) each with a volume of 10.0 cm3 from 15 °c to 25 °c.

Answer 1

Energy required to heat a mass
`m` having specific heat capacity
`c` causing a temperature difference of
`\Delta T` is given by:

`E=mc\Delta T`

a)gold

Density
`d=19.32 g/cm^3`

Volume,
`V=10cm^3`(given)

Mass of gold, M=d×V

`M=19.32g/cm^3*10cm^3=193.2g`

Specific heat capacity of gold,
`c=0.129J/g ^oC`

`\Delta T=25^oC-15^oC=10^oC`

`\Rightarrow E=mc\Delta T=193.2g* 0.129J/g ^oC * 10^oC=249.2J`

b)Aluminium

Density
`d=2.7g/cm^3`

Volume,
`V=10cm^3`(given)

Mass of gold, M=d×V

`M=2.7g/cm^3*10cm^3=27g`

Specific heat capacity of gold,
`c=0.902J/g ^oC`

`\Delta T=25^oC-15^oC=10^oC`

`\Rightarrow E=mc\Delta T=27g* 0.902J/g ^oC * 10^oC=243.5J`