Question

How much heat do you need to raise the temperature of 150g of ice from -30c to -15c?

Answer 1

Answer : Heat required is 9418.5 J

Explanation :

Given that,

Mass of the ice, m = 150 g

Initial temperature of the ice,
`T_i=-30\ ^0C`

Final temperature of the ice,
`T_f=-15\ ^0C`

We know that heat required is given by :

`Q=mc\Delta T`

`\Delta T` is change in temperature or
`\Delta T=T_f-T_i`

c is the specific heat,
`c=4.186\ J/g\ ^0C`

`Q=150\ g* 4.186\ J/g\ ^0C* (-15-(-30))\ ^0C`

`Q=9418.5\ J`

Hence, this is the required solution.

Answer 2

Heat required = mass (g)*specific heat (c)* Temperature change (ΔT)

Given,
mass = 150 g, specific heat = 4.187 J/g.K, ΔT = -15 -(-30 = -15+30 = 15 K

Therefore,

Heat, H = 150*4.187*15 = 9420.75 J