Transcript Molarity Part II

Solutions and Molarity
1.
13.8 L of CO2 @ STP is dissolved in 250.0 mL of water. What is the
molarity of the resulting solution?
13.8 L CO2
Molarity
x 1 mol CO2
22.4 L
=
0.250 L
=
2.46 M
2. If a 1.89 M solution is made by dissolving chlorine gas in 600.0 mL of
water, what volume of Cl2 gas was dissolved?
0.600 L
x 1.89 mol
1L
x 22.4 L
1 mol
=
25.4 L of Cl2 gas
3.
Calculate the molarity of a solution when 2.96 x 1024 FU’s of CaF2 are
dissolved in 0.500 L of water?
2.96 x 1024 FU
x 1 mol
6.02 x 1023 FU
Molarity =
=
0.500 L
9.83 M
4.
How many molecules are dissolved in 1.00 L of water if the molarity
of the H2SO4 solution is 0.2 M?
1.00 L
x
0.2 mol
1L
x
6.02 x 1023 molecules
1 mol
=
1 x1023 molecules
5.
Excess sodium hydroxide solution is added to 80.0 mL of 0.336 M
ZnCl2, calculate the mass of zinc hydroxide that will precipitate.
2 NaOH (aq)
→ Zn(OH)2(s)+
+ZnCl2(aq)
0.0800 L
0.0800 L ZnCl2
2NaCl (aq)
?g
x 0.336 mole
1L
x
1 mole Zn(OH)2
1 mole ZnCl2
= 2.67 g Zn(OH)2
x
99.4 g
1 mol
6.
Calculate the volume of 0.100 M HCl solution that is required to
completely neutralize 250.0 mL of 0.200 M Ba(OH)2 solution.
2HCl(aq)
?L
+
Ba(OH)2 (aq)
→
BaCl2(aq)
+
2H2O (l)
0.2500 L
0.2500L Ba(OH)2 x 0.200 mole
1L
x
2 mole HCl
1 mole Ba(OH)2
= 1.00 L
x
1L
0.100 mol