Question

the density of a certain aqueous solution is 1.17g/ml, and the solution is 3.57% by mass NaOH. how many ml of this solution would you need to use in order to prepare 100.0 ml of .150 M NaOH solution?

I'm not sure where to start and what the process to go through would be... Help!

Answer 1

The density of the solution is 1.17 g/mL. How much does a liter weigh?
1.17 g/mL x 1000 mL = ?? grams = mass of soln.

How much of that is NaOH? 0.0357%; therefore, ?? g soln x 0.0357 = ??g NaOH.(The remainder is the mass of the water in the solution).

How many mols NaOH is that? ??gNaOH/molar mass NaOH.

So that many mols in a liter of solution is the molarity.
Then M x mL = M x mL OR
M x mL = 0.150 x 100 mL.
You know M from above and that leaves only mL. Solve for that.
Check my thinking. Check my work. Post your work if you get stuck.

Answer 2

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