[maria123]

Please help me, I have been trying to figure these out for so much time. any step by step answers would be great! They will be on an exam tomorrow and I still do not know how to solve them!


1. When 0.1 mols of solid silver nitrate is added to 1.0 L of clear, SATURATED solution of Ag2CrO4 (Ksp = 2.4 x 10^-12) will a precipitate be formed? (how is this determined?)

2. The Ksp for AgBr is 5 x 10^-13. If you mix 500 mL of 1.4 x 10^-6 M AgNO3 with 500 mL of 1.4 x 10^-6 M NaBr, then

a. Ag Br will precipitate

b. no precipitation will occur

c. 7.0 x 10 ^-6 mol of AgBr will form

d. the concentration of Ag+ will be 1.4 x 10^-6M.

e. sodium bromide will precipitate

3. To a saturated solution of zinc hydroxide, suffiecient Zn (NO3)2 is added until the Zn2+ concentration is 0.10 M. The pH of the solution is what? The solubility of zinc hydroxide at 25 degrees celcius is 3.7 x 10^-4 g/L

[maria123]

A 2 x 10^-3 M solution of MnSO4 is gradually made more basic by adding NaOH. At what pH will manganese hydroxide begin to precipitate? [Ksp of Mn(OH)2 = 2 x 10^-13]
Thank you!

[Ciubba]

I would start by finding an equation that models this situation. The problem mentions Ksp, so you should be able to come up with a solubility equation. Also, consider what it means that MnSO4 is in solution.

[Corribus]

You are required to show work to receive help on this forum.

[Arkcon]

I'd like to welcome you, maria123: to the Chemical Forums.  According to the Forum Rules{click}, we want to see your attempt, so please click on that link, read the contents, and comply with our rules, so we can help you. 

I hope you don't mind that I combined your two Urgent! posts, its useful to have all the questions together, so we can begin to help.