Final answer:
To calculate the molar heat capacity of C2H2Cl2, first determine the specific heat capacity using the heat provided, mass of the substance, and temperature change, then multiply by the molar mass of C2H2Cl2.
Step-by-step explanation:
The question asks for the calculation of the molar heat capacity of C2H2Cl2 (dichloroethane) using the amount of heat required to raise the temperature of a given mass of the substance. To find the molar heat capacity, we use the formula q = mcΔT, where q is the heat absorbed, m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature.
Given that 8.71 × 103 J of heat is needed to raise the temperature of 455.0 g of C2H2Cl2 from -7.9°C to 9.6°C, we can calculate the specific heat capacity (c) first by rearranging the formula to c = q / (mΔT). Then, to find the molar heat capacity, we need to multiply the specific heat capacity by the molar mass of C2H2Cl2. The molar mass is obtained by adding the atomic masses of two carbon atoms, two hydrogen atoms, and two chlorine atoms from the periodic table.