How many mL of a stock solution of 13.0 M HNO3 would you have to use to prepare 0.500 L of 0.200 M HN?

Question

please help

Answer 1

C1 V1 = C2 V2
(13.0 M) V1 = (.200 M)(.500 L)
V1 = (.200)(.500)/(13.0) = 0.00769 L = 7.69 mL

Add up 7.69 mL of stock solution to 0.500 L = 500 mL - 7.69 mL = 492.31 mL of distilled water and it's done.