Question

When 26.6 g of potassium chloride dissolves in 300g of water, the temperature drops from 26.1°C to 11.7°C. The calorimeter's heat capacity is:

a) 14.4 J/°C
b) 10.8 J/°C
c) 7.2 J/°C
d) 4.6 J/°C

Answer 1

The chemistry question asks for the heat capacity of a calorimeter based on the temperature change caused by the dissolution of potassium chloride in water. By calculating the heat absorbed by the water and knowing that this heat is equivalent to the heat absorbed by the calorimeter, one can determine the calorimeter's heat capacity.

Step-by-step explanation:

The subject of the question involves the determination of the calorimeter's heat capacity when a known mass of potassium chloride dissolves in water and causes the temperature to drop. To calculate the heat capacity of the calorimeter, one needs to understand the heat transfer occurring during the dissolution and how it correlates to the temperature change in the calorimeter.

To find the heat capacity of the calorimeter, we assume all heat lost by the solution is gained by the calorimeter. We use the formula q = mcΔT, where q is the heat absorbed or released, m is the mass of the water, c is the specific heat capacity (which is 4.18 J/g°C for water), and ΔT is the change in temperature. Since the temperature drops, the calorimeter is absorbing the heat released by the dissolution of potassium chloride.

• Calculate the heat absorbed by the solution: q = mcΔT = (300g)(4.18 J/g°C)(11.7°C - 26.1°C)
• Calculate the heat capacity of the calorimeter (Calorimeter's heat capacity = −q/ΔT), which will give the correct option among the multiple-choice answers.