Question

When a small ice cube at -10∘C is put into a cup of water at room temperature, which of the following plays a greater role in cooling the liquid water: the warming of the ice from -10∘C to 0∘C , or the melting of the ice?

a) the warming of the ice from -10 ∘C to 0 .C

b) the melting of the ice

Answer 1

To know which one plays a greater role in cooling the liquid water we have to calculate the heat individually.

We can use the following formula to calculate warming of the ice

Q = mc∆T

Q = heat energy (Joules, J), m = mass of a substance (kg)

c = specific heat (units J/kg∙K), ∆ is a symbol meaning "the change in"

∆T = change in temperature (Kelvins, K)

Heat of fusion = 334.16 J g¯¹

specific heat capacity for solid water (ice) = 2.06 J g¯¹ K¯¹

Question a

Let us calculate for 1 gm of water

Q = 1 x 10 x 2.06 = 20.6 Joules

Question a

Let us calculate for 1 gm of water

Q = 1 x 334.16 = 334.16 Joules

The maximum amount of heat is released when ice melts. Hence melting of the ice will play a greater role in cooling the liquid water.