Chemistry- I NEED HELP!
posted by Pokadot Shorts on .
A particular household ammonia solution (D= 0.97g/ml) is 6.8% by mass.
How many milliliters of this solution should be diluted with water to produce 650 mL of a solution with pH= 11.65?
You need to know the molarity of the NH3 solution. That is
0.97 g/mL x 1000 mL, x 0.068 x (1/17) = ??M. I obtained abouat 4 M BUT you need to do it exactly. I rounded here and there.
Now move to the solution you wish to prepare. If pH = 11.65, then pOH = 2.35 and you can calculate the OH^- from this.
NH3 + H2O ==> NH4^+ + OH^-
Set up Kb expression, plug in NH4^+, OH^-, and Kb and solve for NH3 = ??
Then 4 M x mL = ??M x 650
Post your work if you get stuck. Check my work.