Question

Find the final equilibrium temperature when a 10.0 g of milk at 10.0c is added to 1.60 x 10^2 g of coffee with a temperature of 90.0 c

Answer 1

Heat lost= heat gained, so if x is the equilibrium temperature heat lost is 160(90-x) and heat gained is 10(x-10).
14400-160x=10x-100, 170x=14500, x=14500/170=85.3℃.

Answer 2

Answer: 85.29°C

Explanation:

When two objects with different temperature come into contact with one another, the temperature loss by object with higher temperature is equal to the temperature gain by another object with lower temperature. That is,

Heat loss by the hotter object = Heat gained by by the colder object

Let x represent the equilibrium temperature.

And,

heat capacity = mass × specific heat capacity × change in temperature

Hence, we have

160(90-x) = 10(x-10)

160/10= (x-10)/(90-x)

16 = (x-10)/(90-x)

16(90-x) = x-10

1440 - 16x = x - 10

17x = 1450

x = 1450/17

x = 85.29 °C

The final equilibrium temperature is 85.29 °C