# Basic help with PH

1. Jun 4, 2009

### geffman1

1. The problem statement, all variables and given/known data
We add 0.535 g of NaOH to 100.0 mL of water at 25degrees. What is [H3O+] in this solution at 25degrees?

hey guys, ive practiced these types of questions alot, but ive never came accross one like this before. i tried writing equations and i got this 2NaOH+2H20>>2Na+2H30, but im stuck at the next step. anyhelp would be good. thanks

(p.s) if anyone could sit down with me on msn or something for 20minutes ive got about 15 basic question i need help with (ive got the answers). thanks

2. Jun 4, 2009

### symbolipoint

If that NaOH concentration is not too excessive for the model, you can try finding expected [OH-] and then use pH + pOH = 14

3. Jun 4, 2009

4. Jun 4, 2009

### geffman1

ta, could you help me write the equation then because i cant get it to balance good? tnaks

5. Jun 4, 2009

### Staff: Mentor

Your equation won't have H+ in it.

Check the page I have lined to. To start you have to calculate [OH-].

6. Jun 4, 2009

### geffman1

can i just write it like this..NaOH>Na+OH

7. Jun 4, 2009

### Staff: Mentor

Don't ignore charges, these are ions. But otherwise you are on the right track, this is just a simple dissociation.