# Chem

posted by .

The question is telling me that NaOH (24.00 grams) is diluted in water (750 mL). Find the pH and pOH. This is what I did so far:

NaOH ---> Na+ + OH-

NaOH:
mass = 24.00 grams
v= 750 ml = 0.750 L
M= 40.00 grams/mol
n= 0.6000 mol
c= 0.800 mol/L

Since NaOH dissociates 100%, the concentration of OH- = the concentration of NaOH. Therefore,

pOH = -log [0.800]
= 9.69 x 10^-2

[pH][pOH] = 1 x 10^-14
pH = 1 x 10^-14 / 9.69 x 10^-12
= 1.03 x 10^-3

Did I do this correctly?

• Whoops -

[pH][pOH] = 1 x 10^-14
pH = 1 x 10^-14 / 9.69 x 10^-12

No,
pH = 1 x 10^-14 / 9.69 x 10^-2

= 1.03 x 10^-13

You know the Ph has to be much higher than 7, nearly 14, because NaOH is a BASE !

• Chem -

The problem here, Lena, is that
[pH][pOH]=1 x 10^-14 is not true.
Two errors.
pH + pOH = pKw = 14 which is the log form. If you wish to use the regular form it is
or (H^+)(OH^-)=Kw = 1 x 10^-14
You mixed the two.

• oops, too. -

Sorry. It's still early for me. DrBob222 came out DrGog222.

## Similar Questions

1. ### CHemistry

im not sure how u solve these types of problems... How many moles of NaOH are contained in 200ml of a 0.1M of NaOH?
2. ### Chemistry

What is the pH of the solution created by combining 12.20 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
3. ### Chemistry

If 25.5 grams of NaOH is dissolved in 750 ml of water, find: [H+]= [OH-]= pH= pOH=
4. ### Science (Chemistry)

I'm not sure how to do a couple of problems on my chemistry worksheet. Can you please help me?
5. ### Chemistry

Given the following equation: Na2O + H2O ---> 2 NaOH. How many grams of NaOH is produced from 1.20 x 10^2 grams of Na2O?
6. ### Chem

Then, determine the final volume needed to dilute 20.0 ml of 1.00 M NaOH to 0.25 M. Next, find the volume of water which needs to be added. Finally, determine the moles and the mass in grams of NaOH in the solutions. Do I take 60 ml …
7. ### Chemistry

A solution of NaOH(aq) contains 7.7 grams of NaOH in 93 mL of solution. Calculate the pH at 25◦C. ---- 7.7 grams x (1 mol/39.997 grams) = 0.19 mol 0.19 mol/0.093 L = 2.07 M pOH = -log(2.07) = -0.316 ---- Am I doing anything wrong?
8. ### Chemistry

100g of water is added into 10.6M NaOH solution. The diluted NaOH then neutralized completely with H2SO4 . density of NaOH is 1.08g/ml . calculate the mole fraction of NaOH in diluted solution .
9. ### Chemistry

100g of water is added into 10.6M NaOH solution. The diluted NaOH then neutralized completely with H2SO4 . density of NaOH is 1.08g/ml . calculate the mole fraction of NaOH in diluted solution .
10. ### Chemistry

How many grams of NaOH would you dissolve in pure water to make 400 mL of a 2.5% NaOH solution ?

More Similar Questions

Post a New Question