Answer to Question #288326 in General Chemistry for Kim

Question

Consider a buffer made up of 0.10 M H2PO4^- and 0.32 M HPO4^2-. The Ka of H2PO4^- is 6.2x10^-8. What is the resulting pH when 1 liter of the buffer is mixed with 0.01 mol HClO4? Assume no change in volume occurs upon addition of the acid.

A. 8.54

B. 6.76

C. 7.66

D. 8.43

If we dissolve CaCO3 in water, we get the following equilibrium:

CO3^2-(aq)+H2O(l) =HCO3^-(aq) + OH^-(aq)

0.675 grams of calcium carbonate is dissolved in enoughwater to make 500 mL of solution. The MW of CaCO3 is 100 g/mol and the Kb of CO3^2- is 2.1x10^-4. What is the initial concentration of the carbonate ion?

What is the equilibrium concentration of the hydroxide ion?

What is the pOH of the solution?

What is the pH of the solution?

Answer 1

we dissolve CaCO3 in water, we get the following equilibrium:

CO3^2-(aq)+H2O(l) =HCO3^-(aq) + OH^-(aq)

0.675 grams of calcium carbonate is dissolved in enoughwater to make 500 mL of solution. The MW of CaCO3 is 100 g/mol and the Kb of CO3^2- is 2.1x10^-4. What is the initial concentration of the carbonate ion