Wednesday

April 23, 2014

April 23, 2014

Posted by **Jonah** on Sunday, March 17, 2013 at 9:33pm.

1) Calculate the molar solubility of AgBr in 3.0×10^−2 M AgNO3 solution.

2) calculate the molar solubility of AgBr in 0.10 M NaBr solution.

I tried solving using this the quadratic formula, but it didn't work.

I started with these equations and then solved for x, but none of them gave me the correct answer.

1) 5.0 x 10^-13 = (x + 3.0 x 10^-2)(x)

2) 5.0 x 10^-13 = (x)(0.10+x)

- Chemistry -
**DrBob222**, Sunday, March 17, 2013 at 9:47pmTHANKS for showing your work. If you had shown your math work I could have checked the error. You must have made a math error. The chemistry is OK. And you need not solve the quadratic with either of them.

- Chemistry -
**Jonah**, Sunday, March 17, 2013 at 11:02pmHow would I do it without the quadratic formula?

- Chemistry -
**DrBob222**, Sunday, March 17, 2013 at 11:22pmMake the assumption that x is small in comparison to 0.03(another way of saying x + 0.03 = 0.030). Then

5.0E-13 = (x)(0.03)

x = (5.0E-13/0.03) = 1.67E-11

Then you check the assumption to see if you must go back and solve the quadratic. So 1.67E-11 + 0.03 = essentially 0.03---not even close). Since the Ksp has only 2 s.f. in it I would round that 1.67E-11M to 1.7E-11M.

You were right to include the x in the set up because some problems will not allow you to ignore the x. I always make the assumption, then check it when I finish. If the easy answer is within 5% (I think most texts use the 5% rule now) I let it stand. If the error is more than that I go back and solve the quadratic.

**Related Questions**

chemistry - Find the solubility of AgBr in 3.9 M NH3 [Ksp of AgBr = 5.0 10-13 ...

Chemistry - You have amisture that is 0.100mol/L in each of the following ions: ...

Chem - (a) The molar solubility of Ag2CrO4(s) at 35°C is 1.3 10-4 mol/L. ...

chemistry - Calulate the molar solubility of Al(OH)3 in water. (Ksp = 3 x 10^-34...

Chemistry - what is the molar solubility of lead sulfate in 1.0 X 10^-3 M Na2SO4...

chem - The molar solubility of MgF2 at 25°C is 1.2 10-3 mol/L. Calculate Ksp. i...

Chemistry - What is the solubility of silver chloride in water at 25C? (Ksp = 1....

chemistry - Calculate the solubility of silver chloride in a 0.1 mol/L solution ...

College Chemistry - Calculate the molar solubility of Mn(OH)2 in grams per liter...

chemistry - how do i calculate the molar solubility of AgBr in .10M NaBr?