A quantity of hot water at 100oC is added to 400g of water at 10oC until the temperature of the mixture is 60oC.
Calculate the mass of the hot water added. [Specific heat capacity of water =4200JKg-1 K-1]
- 200g
- 320g
- 400g
-
500g
The correct answer is: D
Explanation
Heat lost by hot water = Heat gained by cold waterM x 4200 x (100 - 60 = 0.4 x 4200 x (60 - 10)
4200m x 40 = 0.4 x 4200 x 50
40m = 0.4 x 50
m = \(\frac{0.4 \times 50}{40}\) = 0.5kg
= 500g