Calcualte the enthalpy change when infinitely dilute solution of CaCI_(2) and Na_(2)CO_(3) are mixed. Delta_(f)H^(Theta) for Ca^(2+)(aq), CO_(3)^(2-)(aq), and CaCO_(3)(s) are -129.80, -161.65, and -288.50 kcal mol^(-1) respectively.

Calcualte the enthalpy change when infinitely dilute solution of CaCI_

1.	Calcualte the enthalpy change when infinitely dilute solution of CaCI_(2) and Na_(2)CO_(3) are mixed. Delta_(f)H^(Theta) for Ca^(2+)(aq), CO_(3)^(2-)(aq), and CaCO_(3)(s) are -129.80, -161.65, and -288.50 kcal mol^(-1) respectively.
Answer» Solution :Infinitely DILUTE SOLUTIONS are completely ionised. `{:(Caunderset(darr).^(2+)CI_(2)^(2-) +Na_(2)^(2+)CO_(3)^(2-)),(CaCO_(3)darr+2NaCI):}` `{:(Caunderset(darr).^(2+)+2CI^(Theta)+2Na^(darr)+CO_(3)^(2-)),(Ca^(2+)+CO_(3)^(2-)+2Na^(o+)+CO_(3)^(2-)):}` `Ca^(2+) +CO_(3)^(2-) rarr CaCO_(3)(s)` `-DELTAH^(Theta) = Delta_(f)H^(Theta)CaCO_(3) -[Delta_(f)H^(Theta)ca^(2+)+Delta_(f)H^(Theta)CO_(3)^(2-)]` `= - 288.5 -(-129.80-161.65)` `DeltaH^(Theta) = 2.95 kcal`