Chapter 14 practice problems
1. What mass of LiCl must be dissolved to make a 0.194M solution that has a volume of 1.00L?
0.194 moles
1L
X
42.5g
1 mol
X
1L
=
8.25g
2. What mass of KNO3 must be dissolved to make 2.5L of a 0.800M solution?
0.8 moles
1L
X
101g
1 mol
X
2.5L
=
202g
3. What is the molarity of a solution that contains 4.13g of MgBr2 in 0.845L of solution?
4.13g
0.846L
X
1 mol
184g
= 0.027M
4. How many milliliters of 3.0M phosphoric acid (H3PO4) can be made from 95 mL of a 5.0M H3PO4
solution?
M1 = 5.0M
V1 = 95mL
M2 = 3M
V2 = ?
M1V1=M2V2
V2 = M1V1/M2
V2 = (5.0)(95) / 3 = 158.3mL
5. If you dilute 20.0 mL of a 3.5M solution to make 100.0mL of solution, what is the molarity of the
dilute solution?
M1 = 3.5M
V1 = 20mL
V2 = 100mL
M2 = ?
M1V1=M2V2
M2 = M1V1 / V2
M2 = (3.5)(20) / 100 = 0.7M