Question

In today’s experiment you will need to make 15 mL of a 3.0 M HCl solution. You will be diluting from a stock solution of 4.5 M HCl. Use your dilution calculation (M1V1 = M2V2) to determine how much of the original stock solution you will need.  How much water will you be adding to the acidic solution?

Answer 1

We will use equation,

M1 V1 = M2 V2

where,  

M1 = Initial molarity = 4.5 M

V1 = Initial volume = to be calculated.

M2 = Final molarity = 3 M

V2 = Final volyme = 15 mL

Putting this in above equation we get,

4.5 M x V1 = 3 M x 15 mL

4.5 M x V1 = 45 M/mL

therefore,

V1 = 45 M/mL / 4.5 = 10 mL

Therefore we must diluted 10 mL 4.5 M HCl solution to make 3 M 15 mL HCl solution. Total volume is 15 mL therefore additional 5 mL water will be added

Ans = 10 mL stck solution

5 mL water.