Section 3: Dilutions

• Dilutions• Calculations

Dilutions

lowers concentration, or molarity

but…

total moles of solute does not change

A. Dilutions

mol L

M = mol

LM =

A. Dilutions

6 molin 100 mL

6 molin 200 mL

same# of mol

A. Dilutions

Dilutions

A. Dilutions

initial Molarity

initial Volume

Molarity of dilute solution

Volume of dilute solution

How many mL of 2.00 M MgSO4 must be diluted to prepare 100 mL of 0.400 M MgSO4?

V1 = (0.400 M) x (100 mL) = (2.00 M)

B. Calculations

Finding Volume (V1)

20.0 mL

M1

V2 M2

V1

(2.00 M) x V1 = (0.400 M) x (100 mL)

200 mL of 10.0 M NaOH is diluted to 500 mL, what is the molarity of the dilute solution?

M2 = (10.0 M) x (200 mL) = (500 mL)

B. Calculations

Finding Molarity (M2)

4.00 M

M1 V2

M2

V1

(10.0 M) x (200 mL) = M2 x (500 mL)