Question

100ml of water at 20 C and 100ml of water at 40 C are mixed in calorimeter until constant temperature reached. Now temperature of the mixture is 28 C. Water equivalent of calorimeter is

a) 50J
b)104.5J
c) -24.2J
d) 209J

Answer 1

B one is your answer

Answer 2

Answer:

water equivalent = 50 J

Explanation:

In this question

We have been given that

100 ml of water at 20 C and 100 ml of water at 40 C are mixed in calorimeter  temperature of the mixture is 28 C.

Now,

Heat lose =  Heat gained

$100\times (40 - 28)\times 1$ = $100\times (28 - 20)\times 1 + water equivalent\times 8$

1200 = 800 + $water equivalent\times 8$

$water equivalent\times 8$ = 1200 - 800

$water equivalent$ = $\frac{400}{8}$

$water equivalent$ = 50 J