∆H of
★Ca(HCO3)2→CaCO3 + CO2 + H2O
and
★Ca(HSO4)2→ CaSO4+ SO2 + H2O???
dHrxn = (n*dHf products) - (n*dHf reactants)
Look up dHf for each and calculate.
To determine the enthalpy change (∆H) for the reactions you provided, we need to look up the standard enthalpies of formation (∆Hf) for each compound involved and apply Hess's Law.
Step 1: Find the ∆Hf values
Look up the standard enthalpies of formation (∆Hf) for each compound involved in the reactions:
- ∆Hf of Ca(HCO3)2 (calcium bicarbonate)
- ∆Hf of CaCO3 (calcium carbonate)
- ∆Hf of CO2 (carbon dioxide)
- ∆Hf of H2O (water)
- ∆Hf of Ca(HSO4)2 (calcium bisulfate)
- ∆Hf of CaSO4 (calcium sulfate)
- ∆Hf of SO2 (sulfur dioxide)
Step 2: Apply Hess's Law
Hess's Law states that the enthalpy change of a reaction can be calculated by considering the difference in enthalpy between the reactants and products.
For the first reaction: Ca(HCO3)2 → CaCO3 + CO2 + H2O
The enthalpy change (∆H) is equal to the sum of the ∆Hf values of the products minus the sum of the ∆Hf values of the reactants.
∆H1 = [∆Hf(CaCO3) + ∆Hf(CO2) + ∆Hf(H2O)] - ∆Hf(Ca(HCO3)2)
For the second reaction: Ca(HSO4)2 → CaSO4 + SO2 + H2O
The enthalpy change (∆H) is equal to the sum of the ∆Hf values of the products minus the sum of the ∆Hf values of the reactants.
∆H2 = [∆Hf(CaSO4) + ∆Hf(SO2) + ∆Hf(H2O)] - ∆Hf(Ca(HSO4)2)
Step 3: Calculate the enthalpy change (∆H)
Substitute the values obtained in step 1 into the equations from step 2 and calculate the values.
Note: Make sure to use the correct units for the enthalpies (usually in kJ/mol). Also, double-check that the stoichiometry of the reactions balanced correctly.
By following these steps, you can find the enthalpy changes for the given reactions.