Question

If I have a glass of filled with 300 grams of water at 25 *C then how much ice do I need to add for it to reach a temperature of 5 *C?

Answer 1

About 65 grams of ice, considering the ice has an initial temp of -15 degrees Celsius

Explanation:

We are trying to find the mass of ice here so, the heat gained by the ice is the heat lost by water, also considering the fact that the ice also has to melt. The final temperature of the mixture has to be 5 degrees Celsius

`mcDeltat+mL_(fusion)+mcDeltat= -mcDeltat`

`m(2.1 J/(g°C))(0°C-(-15°C))+m(334 J/g)+m(4.184J/(g°C))(5°C-0°C)= -(300g)(4.184 J/(g°C))(5°C-25°C)`

`386.42 J/g*m= 25104 J`
`m approx65 g`