Question

Calculating specific heat capacity A constant-pressure calorimeter is often used to find the specific heat capacity of a substance if it is not known. A known mass of the substance can be heated and added to water of known mass and initial temperature. Since the specific heat capacity of water is known ( C s,water =4.184J/(g⋅ ∘ C)) , the amount of heat transferred to the water can be calculated by measuring the final temperature of the mixture at thermal equilibrium. This is the same as the amount of heat transferred from the substance according to the law of conservation of energy. Thus we can arrive at the following relationship: − q unknown = −( m unknown × C s,unknown ×Δ T unknown )= q water m water × C s,water ×Δ T water With the unknown substance's mass and change in temperature known, the unknown substance's specific heat capacity can be calculated.

Part C A mass of 47.5 g of an unknown solid initially at 130.0 ∘ C is added to an ideal constant-pressure calorimeter containing 100.0 g of water ( C s,water =4.184 J/(g⋅ ∘ C)) initially at 20.0 ∘ C . After the mixture reaches thermal equilibrium, the final temperature is recorded to be 30.87 ∘ C . What is the specific heat capacity of the unknown solid? Express your answer to three significant figures.

Answer 1

Pastc Heat Balance equation heat lost by the = heat gained by the given mass water. mi ce, CT; -) - ma cz (Tf - Ti) 47:59 xcx( 130 – 30-87) = 100 x 4.1847 (30-87-80) C = 0.965 J/gºc