Question

How many ml of a 14. 0 m nh3 stock solution are needed to prepare 200 ml of a 4. 20 m dilute nh3 solution?.

Answer 1

60 mL

Step-by-step explanation:

200 mL = 0.2 L

We know that:

Molarity = Moles / Liters

So:

4.20 M = moles / 0.2 L

moles = 4.20 x 0.2 = 0.84

Then:

14.0 M = 0.84 moles / Liters

Liters = 0.84 moles / 14.0 M = 0.06 L

Since they want the answer in mL, convert 0.06 to get 60 mL