Chapter U5.8, Problem 6E

Interpretation Introduction

Interpretation:

A lab report must be written on Calorimetry covering purpose of the experiment, procedure, observation, analysis and conclusion.

Concept Introduction:

Calorimetry deals with heat transfer among objects with different temperature until thermal equilibrium is reached.

Answer to Problem 6E

• Purpose of the experiment is to find temperature of water (mixture) when water with two different temperatures is mixed.
• In a closed container 100 g water is taken at 50°C temperature. Then 100 g water at 20°C is added to the container and mixed properly. Then the final temperature is measured with a thermometer.
• The temperature of the mixture of water was found to be 35°C.

Explanation of Solution

As per Calorimetry principle, when a hot object is kept in contact with cold object then the hot object will release heat which will be absorbed by the cold object. The process continues until the temperature of both the object is same. This means thermal equilibrium is attained.

In this experiment temperatures of two different water were 50°C and 20°C.

Final temperature will be $\text{t=}\frac{{\text{m}}_{\text{1}}{\text{t}}_{\text{1}}{\text{+m}}_{\text{2}}{\text{t}}_{\text{2}}}{{\text{m}}_{\text{1}}{\text{+m}}_{\text{2}}}\text{=}\frac{\text{100×50+100×20}}{\text{100+100}}\text{ °C =}\frac{\text{7000}}{\text{200}}\text{ °C= 35°C}\text{.}$

(M₁, t₁) and (M₂, t₂) are mass and temperature of two different water samples and t is the temperature of the mixed water.

Conclusion

The calculated temperature is matched with the observed temperature. The experiment worked well.