00:01
Hi there, here we have one gram of ice and we have to transform it into vapor at 100 degrees.
00:06
So it means that first ice has to be heated from negative 20 degrees c to 0 degree c, where it's with it experience melting and becomes water at 0 degrees c.
00:27
Then it's heated to 100 and then it becomes vapor at 100.
00:37
Means that the overall heat which system needs equals to q1 that is heating from negative 20 c to 0 degrees c then q2 that is melting then u3 that is heating 200 degrees c and then q4 that is vaporization so it means that q equals to c of ice times mass times 0 degree c minus initial temperature plus lambda m, where lambda is the heat of melting, plus heat capacity of water m times 100 degrees c minus 0 degree c and plus plus 100 degrees c minus 0 degree c and plus r times m where r is the heat of vaporization.
01:57
So let's simplify this.
01:59
Now we can proceed to the calculation but first we can put m before the bracket.
02:05
So before the bracket we have 1 .00 times 10 power by negative 3 kilogram.
02:12
So that is multiplied by the following sum.
02:15
That is 2 .11 times 10 power by 3 joules per kilogram kelvin times 20 degrees c.
02:30
And the change in kelvin equals the changing celsius...