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?
- 100oC
- 80oC
-
50oC
- 40oC
The correct answer is: 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
(\(\theta\) - 20) = 3( 20 - 10)
\(\theta\) = 30 + 20
therefore, \(\theta\) = 50ºC