Could Someone Help Me With This Question??

Question

How many mL of 6.00 (M=mol/L) stock solution do you need to make 1.00 liters of 0.100 M of NaOH?

Answer 1

The easiest way to do this type of problem is by using the formula V1M1 = V2M2 where V1 and M1 are the volumes and molarity of the original solution (solution #1) and V2 and M2 are the volume and molarity of the second solution (solution #2). In this particular case you have...

(x liters)(6.00 M) = ( 1.00 liters)(0.100 M)

x = 0.100/6.00

x = 0.01666 liters

Converting to mls, we have 0.01666 L x 1000 ml/L = 16.66 mls = 16.7 mls (to 3 significant figures)

Answer 2

1 liter of 0.1M NaOH contains 0.1 mol of NaOH. 1L of 6M NaOH contains 6 mols of NaOH. To prepare 1L of 0.1M NaOH from a stock solution, you take X mL of the stock solution and add water to 1 L. Therefore your question can be rephrased as follows: how many milliliters of 6M NaOH contain 0.1 mol of NaOH? The answer requires just a simple arithmetic operation, which you can easily do.