Hot water is added to three times its mass of water at 10oC and the resultant temperature is 20oC. What is the initial temperature of the hot water?
-
A.
100oC -
B.
80oC -
C.
50oC -
D.
40oC
Correct Answer: Option C
Explanation
Heat loss = heat gained
mh x ch x (theta)h = mc x cc x (theta)c
mh x ch x ((theta) – 20) = mc x cc x (20 – 10)
ch = cc ; mc = 3mh
therefore, (theta) = 50oC