117k views
2 votes
A busy housewife left 25 g of ice in an open insulated container while she was answering her cellphone. When she returned, the ice at 0 ºC was converted to water at 3.0 ºC. Calculate the energy needed for the ice to totally melt ad reach its present temperature specific heat capacity of water = 4200 J/kgK Specific Latent heat of fusion of Ice = 340 000J/Kg *?

1 Answer

4 votes

Final answer:

The energy required to melt 25 g of ice and increase the water temperature to 3.0 ºC is 8,815 J, which involves the latent heat of fusion and the specific heat capacity of water.

Step-by-step explanation:

A busy housewife left 25 g of ice in an open insulated container, which then transformed into water at 3.0 ºC from its initial state of 0 ºC. To calculate the energy needed for the ice to totally melt and reach this temperature, we consider two processes: the melting of ice and the heating of the resulting water.

The specific latent heat of fusion of ice (α) is 340,000 J/kg, and the specific heat capacity of water (β) is 4,200 J/kgK.

To melt the ice, the energy required (Q1) is given by:

Q1 = m×α

where 'm' is the mass of the ice.

For the 25 g (0.025 kg) of ice:

Q1 = 0.025 kg × 340,000 J/kg = 8,500 J

After melting, the ice becomes water at 0 ºC. Now, to increase the temperature to 3.0 ºC, we use the equation:

Q2 = m×β×ΔT

where ΔT is the change in temperature. Q2 = 0.025 kg × 4,200 J/kgK × 3 K = 315 J

The total energy required is the sum of Q1 and Q2:

Total energy (Q) = Q1 + Q2 = 8,500 J + 315 J = 8,815 J

Hence, the energy needed to melt 25 g of ice and then increase the temperature of the water to 3.0 ºC is 8,815 J.\

User Kontiki
by
8.1k points