# Chemistry

posted by .

3. A chemistry student makes up a 0.10 M solution of NaF(aq) and finds the pH to be 8.09.
a. Explain why the presence of F- in this solution affects the pH.
b. Write out the acid/base equilibrium equation for the reaction of F- with water.
c. Use the measured pH value to solve for the Kb of this reaction.
d. Calculate the product of your calculated Kb and the Ka of HF (found on the table) and explain the familiarity of this number.

• Chemistry -

I will do b and c and from that work you can do a and d.
b.
.........F^- + HOH ==> HF + OH^-
initial.0.1M...........0......0

c.
What pH value did you get? I need a number; let's call that y = OH and and you can substitute the value you measured it to be after converting from pH.
..........F^- HOH ==> HF + OH^-
initial..0.1..........0.....0
change...-y...........y.....y
equil....0.1-y.........y.....y

Kb for F^- = (HF)(OH^-)/(F^-)
You know HF from the measured pH.
You know OH from the measured pH.
You know F^- = 0.1-y
Solve for Kb for F^-

## Similar Questions

1. ### CHEMISTRY

HOW CAN U TELL IF HNO3 +KNO3 IS A BUFFER SOLUTION A buffer solution must contain a weak acid and its conjugate base OR a weak base and its conjugate acid. HNO3 is a strong base and KNO3 is the salt of a strong base (KOH) and a strong …
2. ### Chemistry (A level)

I was given a Chemistry question on the titration of a strong base being added to a weak acid. The question was: "Calculate the pH in a titration when 10.0cm^3 of a 0.10moldm^-3 solution of NaOH is added to a 10.0cm^3 of 0.25moldm^-3 …
3. ### college chemistry

what is the molarity of NaF in the final solution if a solution was prepared by mixing 35.0mL of 0.200M NaF with 28.5mL of 0.350M NaF
4. ### Chemistry

Write the equation for the equilibrium that exists when nitrous acid and sodium acetate are placed in solution together (do not include spectator ions). Using published values for the Ka of nitrous acid and of acetic acid, determine …
5. ### Chemistry

If you add 0.35grams NaF to 150mL of a 0.30M HF, what is the pH of the resulting solution?
6. ### Chemistry

Write the chemical equation showing dihydrogen phosphate and hydrogen phosphate conjugate acid-base relationship. Identify the acid and base. Explain how the equilibrium is shifted as buffer reacts with an acid and reacts with a base.
7. ### Chemistry

Write the chemical equation showing dihydrogen phosphate and hydrogen phosphate conjugate acid-base relationship. Identify the acid and base. Explain how the equilibrium is shifted as buffer reacts with an acid and reacts with a base.
8. ### Chemistry

Write the chemical equation showing dihydrogen phosphate and hydrogen phosphate conjugate acid-base relationship. Identify the acid and base. Explain how the equilibrium is shifted as buffer reacts with an acid and reacts with a base.
9. ### Chemistry

Write the chemical equation showing dihydrogen phosphate and hydrogen phosphate conjugate acid-base relationship. Identify the acid and base. Explain how the equilibrium is shifted as buffer reacts with an acid and reacts with a base.
10. ### chemistry

In standardizing a potassium hydroxide solution, a student finds that 32.60mL of the base solution is needed to titrate 0.5045 grams of KHP to a phenolphthalein end point. In another titration, 26.63mL of this same base solution is …

More Similar Questions