# Chemistry

posted by .

What is initial concentration of a sodium acetate if the pH (at epuilibrium) is measured to be 9.30?

• Chemistry -

............Ac^- + HOH ==> HAc + OH^-
initial.....y........0.......0.....0
change.....-x...............x......x
equil......y-x...............x......x
y = initial concn Ac^- which is our unknown.
pH = 9.30; convert to H^+ which is 5.01E-10
Therefore OH^- = Kw/(H^+) = 1E-14/5E-10 = 2E-5 but you should be more accurate.
Kb for acetate = (Kw/Ka for acetic acid) = (HAc)(OH^-)/(Ac^-)
(Kw/Ka) = (x)(x)/(y-x)
For x you insert 2E-5; solve for y.

## Respond to this Question

 First Name School Subject Your Answer

## Similar Questions

1. ### Chemistry

I just did a lab on Acids and Bases and I am having trouble with the lab questions I was given to complete. Concentration of NaOH: 0.09999 M Volume of NaOH: 3.25 mL # moles of NaOH: 0.325 moles Initial Concentration of Weak Acid: ?
2. ### Chemistry (Acids and Bases)

I just did a lab on Acids and Bases and I am having trouble with the lab questions I was given to complete. Concentration of NaOH: 0.09999 M Volume of NaOH: 3.25 mL # moles of NaOH: 0.325 moles Initial Concentration of Weak Acid: ?
3. ### chemsitry

calculate the molarity of sodium in 12.4g of sodium acetate diluted in 100mL of ID water, and calculate concentration of both sodium and acetate ion in units of mg/mL,mg/L,and ug/mL?
4. ### chemsitry

calculate the molarity of sodium in 12.4g of sodium acetate diluted in 100mL of ID water?
5. ### Chemistry

20 ml of 0.1 M acetic acid was mixed with 25 ml of 0.1 M Sodium Acetate. The pH was measured to be 4.43. 5 ml of 0.1 M Sodium Hydroxide was added to the buffer and the pH was measured to be 4.60. Calculate the pH of the buffer before …
6. ### Chemistry

Calculate pH of an acetate buffer containing 27.5 mM acetic acid (pKa is 4.74) and 50 mM sodium acetate. When a 30 mM aq solution of sodium acetate was prepared in the lab it had a pH of 8.8. Calculate the amount of acetic acid (in …
7. ### Chemistry

If I add 2ml of .1M of NaOH to a buffer system containing sodium acetate and acetic acid, what will happen to the acetate concentration?
8. ### Chemistry Help

You are required to make 500 mL of a buffer solution with pH = 5.0 and a total acetate concentration of 0.1000 M. You are supplied with solid sodium actetate (CH3COONa) and 2.00 M hydrochloric acid. What mass of sodium acetate and …
9. ### Chemistry

We did a lab about the heat hydration of sodium acetate with water. I got that the enthalpy of anhydrous sodium acetate is exothermic while the enthalpy of trihydrate sodium acetate is endothermic. Also that the enthalpy of the hydration …
10. ### science;chem

The hydrolysis of ethyl acetate (CH3COOC2H5) by sodium hydroxide yields ethanol (C2H5OH) and sodium acetate (NaO2CCH3) by the reaction shown, which follows second order kinetics. In an experiment 500 mL of 0.1 M ethylacetate in water …

More Similar Questions