Question

A 0.500 L solution of 5 M Hydrochloric acid stock solution is used to make a diluted Hydrochloric acid solution of 2.08 M . How much water has to be used to dilute the stock solution

Answer 1

Answer:

0.702 L H₂O

Explanation:

To find the volume of water needed to dilute the stock solution, you need to (1) find the moles of the stock solution (via molarity formula), then (2) find the volume of the diluted solution (via molarity formula), and then (3) find the volume of water needed.

(Step 1)

Molarity (M) = moles / volume (L)                 <----- Molarity formula

5 M = moles / 0.500 L                                  <----- Insert values

2.5 = moles HCl                                           <----- Multiply both sides by 0.500

(Step 2)

Molarity = moles / volume                           <----- Molarity formula

2.08 M = 2.5 moles / volume                      <----- Insert values

(2.08 M) x volume = 2.5 moles                   <----- Multiply both sides by volume

volume = 1.20 L                                           <----- Divide both sides by 2.08

(Step 3)

Diluted Volume = 1.20 L

Stock Volume = 0.500 L

Water Volume = ? L

Diluted Volume = Stock Volume + Water Volume

1.20 L =  0.500 L + Water Volume

0.702 L = Water Volume