Question

1 When 25 cm of 1.0 mol/dmº copper sulfate solution was mixed vith an excess of zinc

powder, the temperature of the solution rose by 50.6 °C. Calculate the energy change
for the reaction in kJ/mol.
CuSO4(aq) + Zn(s) + Cu(s) + ZnSO4(aq)
?

Answer 1

See explanation

Step-by-step explanation:

From the formula for heat;

q (enthalpy change) = (mass of solution) x (specific heat capacity) x (temperature change)

Since the density and heat capacity of the solution are the same as that of pure water.

Mass of copper sulphate solution = 50 g

Heat = 50 * 4.18 * 50.6°C

Heat = 10575.4 J

Number of moles = 1 * 25/1000 = 0.025 moles

10575.4 J/ 0.025 moles = 432016 J/mol/1000

= 423 KJ/mol

or

q = - 423 KJ/mol