00:01
To determine how much energy in calories is released when 45 grams of water at 55 degrees celsius is frozen to ice at zero degrees celsius, we need to carry out two calculations.
00:15
First, we need to cool the water.
00:20
The heat required to cool the water will be equal to the specific heat of liquid water, 1 .00 calories per gram degree celsius, multiplied by its mass, 45 grams, multiplied by its change in temperature.
00:42
We're going to a final temperature of zero degrees celsius from an initial temperature of 55 .0 degrees celsius.
00:50
So we'll be releasing 2475 calories.
00:59
Then we're going to freeze the water at zero degrees celsius.
01:08
The heat required for that will be equal to its mass, 45 grams, multiplied by the heat of fusion.
01:21
Heat of fusion is the melting.
01:23
We want freezing, so it's just going to be the negative of that value, the negative of 80 calories per gram...