00:01
Hi, so to solve for this we will write the involved temperatures.
00:10
We have negative 16, this will be, sorry, negative 16 degrees celsius, this will be heated up to zero degrees celsius, and then 100 degrees celsius, and then to the final temperature 141 degrees celsius.
00:26
So from negative 16 to zero there will be temperature change.
00:30
At zero degrees celsius there will be phase change.
00:33
This is from ice to liquid water, and then from zero to 100 there will be temperature change.
00:39
At 100 degrees celsius there will be phase change.
00:42
This is the boiling point of water, so from liquid to steam.
00:45
From 100 to 141 another temperature change.
00:49
So the amount of heat required for this will be q1, this will be q2, q3, q4, and q5.
00:56
Total amount of heat for the whole process will be the sum of q1, q3, plus q4, plus q5.
01:08
So we will calculate the amount of heat individually.
01:11
Q1, this is temperature change, this is mass, multiplied by the specific heat capacity, and then the change in temperature, and this is for ice.
01:21
Mass of the sample is 55 grams.
01:24
A specific heat capacity of ice is 2 .03 joules per gram degree celsius.
01:31
The change in temperature is zero minus negative 16, and then we will convert joules to kilojoules.
01:40
1000 joules is one kilojoule, so that means we could cancel grams, and then degrees celsius, then joules, and this will be 1 .79 kilojoules.
01:55
For q2, this is phase change from ice to liquid water.
01:59
So number of moles multiplied by the enthalpy of fusion.
02:02
Number of moles, we have 55 grams, divided by the molar mass of water, 18 .02 grams.
02:09
Enthalpy of fusion for water is 6 .01 kilojoules per mole, so that means we could cancel grams, moles, and this will be 18 .34 kilojoules...