Answer to Question #172643 in General Chemistry for John

Question

determine the enthalpy change for the reaction:

Zn(s) + Cu2+(aq) → Cu(s) + Zn2+(aq)

Answer 1

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

q = 50g (from the 50cm cubed) x 4.18 x 6.3 = 1316.7 J

also, number of moles = concentration x volume divided by 1000

n = 1.0 x 50 / 1000 = 0.05 moles

so 0.05 moles = 1316.7 J

1 mole = 1316.7 divided by 0.05 = 26334 J and if we divide that by 1000 = 26.334 kJ

or q = - 26.334kJ/mol