[conb]

 have two problems that I have attempted but feel that I have done something wrong or missed a step.

1. What will the volume of a .50 M solution be if it contains 25 grams of calcium hydroxide.
I set it up as Molarity equations, Molarity=moles/liters.
25g/74gCalcium Hydroxide=.340

.5M=.340/Liters

Answer is 680mL but I dont know how they got that.

2.How many grams of ammonia are present in 5.0L of a 0.050M solution?
Set up- 5L=5g.....5g(.050M)=.25
.25(17gAmmonia)=4.25g
Actual answer 4.3 grams.
Is that the right way to do it?

[AWK]

1. According to definition of molar concentration
c=n/V        (V in dm³)
You know: c - concentration -0.50
and n - number of moles - 0.34

result shold be 0.68 dm3 (two significant digits)

2. round to 2 significant digits