200. Grams of copper at 15°C are mixed with 200 grams H20 at 60°C. If the final

temperature of the mixture is 42.7oC, what was the mass of the water?

29.467 g

Explanation:

From the question;

Mass of copper is 200 g

Initial temperature of copper is 15°C

Mass of water is 200 grams

Initial temperature of water is 60°C

Final temperature of the mixture is 42.7 °C

We are required to calculate the mass of water

Step 1: Heat absorbed by copper

Quantity of heat, Q = Mass * specific heat capacity * change in temperature

Specific heat capacity of copper = 0.385 J/g°C

Change in temperature, ΔT = 42.7°C - 15°C

= 27.7° C

Q = mcΔT

Q = 200 g * 0.385 J/g°C * 27.7°C

= 2132.9 Joules

Step 2: Quantity heat released by water

Specific heat capacity of water is 4.184 J/g°C

Change in temperature, ΔT = 42.7°C - 60°C

= - 17.3 °C

Assuming the mass of water is m

Then

Q = m * 4.184 J/g°C * 17.3 °C

= 72.3832m joules

Step 3: Calculating the mass of water

The heat gained by the copper metal is equal to the heat released by the water.

Therefore;

2132.9 Joules = 72.3832m Joules

m = 2132.9 J : 72.3832 J

= 29.4668

= 29.467 g

Therefore, the mass of water is 29.467 g