QUATERLY 3 REVIEW- key
Chapter 12 – Stoichiometry
6. a. 537g Fe
b. 93.1g Fe
7. 14.7g of Ba3(PO4)2; Limiting reactant- Ba(NO3)2; Excess left over- 9.5g Na3PO4; 83.7% yield
Chapter 13 – Solids and Liquids
1.
2.
3.
4.
5.
dipole-dipole, dispersion
dispersion
dispersion
H-bonds, dipole-dipole, dispersion
Solids- definite shape/volume, organized & close, vibrate around fixed point. Liquids- definite volume, shape of container, unorganized
yet close, move past each other.
6. network
7. metals
8. molecular
9. amorphous
10. ionic
11. strong IMF = low volatility, low vapor pressure, high bp
12. 28.0 g/mol
Chapter 14 – Gases
13.
14.
15.
16.
1180 mmHg
180. kPa
493°C
80. L
Chapter 15 – Solutions
21. Unsaturated-dissolves, saturated-sinks to bottom,
supersaturated-excess crystallizes
22. temp↑ solubility solids ↑
solubility gases 
pressure ↑ solubility gases ↑
23. soluble
25. soluble
17.
18.
19.
20.
440. L
43.6 g/mol
7.94 L
93.2 K
24. insoluble
26. insoluble
27. a. 40 grams
c. CO2 downwards
b. ~7 grams
28. 9.00 g
29. 4.2 mL
30. Molarity= mol solute/L of solution
Molality = mol solute/kg of solvent
31. AlCl3
32. Fp = -4.76°C, bp = 101.31°C
EXTRA PRACTICE PROBLEMS – key
1. What relationships can be determined from a balanced chemical equation?
Mole to mole
2. Explain why mole ratios are central to stoichiometric calculations.
Since atoms and molecules have different masses, we need to compare moles to have the
correct number of particles.
3. How many grams of silver phosphate are produced?
3AgNO3 + Na3PO4  Ag3PO4 + 3NaNO3
200.0g AgNO3 x 1 mole AgNO3 x 1 mole Ag3PO4 x 418.58g Ag3PO4 =
169.88g AgNO3
3 mole AgNO3
1 mole Ag3PO4
200.0g Na3PO4 x 1 mole Na3PO4 x 1 mole Ag3PO4 x 418.58g Ag3PO4 =
163.94g Na3PO4
164.3g Ag3PO4
1 mole Na3PO4
510.6g Ag3PO4
1 mole Ag3PO4
4a. What volume of hydrogen at STP is produced from the reaction of 50.0 g of Mg and 75.0 g
of HCl?
Mg + 2HCl  MgCl2 + H2
50.0g Mg x 1 mole Mg x 1 mole H2 x 22.4L H2 = 46.1 L H2
24.31g Mg
1 mole Mg 1 mole H2
75.0g HCl x 1 mole HCl x 1 mole H2 x 22.4L H2 = 23.0 L H2
36.46g HCl
2 mole HCl 1 mole H2
so HCl is LR
b. How much excess reactant is left over?
75.0g HCl x 1 mole HCl x 1 mole Mg x 24.31 Mg = 25.0g Mg reacted
36.46g HCl
2 mole HCl 1 mole Mg
so 50.0g – 25.0g=25.0g
5. A balloon is filled with 3.0 L of helium at 1 atm. What is the volume when the balloon rises
to an altitude where the pressure is only 0.25 atm? (assume temperature remains constant.)
P1 V1 = P2 V2
=
(1.0 atm)(3.0L)=(0.25 atm)(X)
12L
6. The gas left in a used aerosol can is at a pressure of 1 atm at 27°C. If this can is thrown into a
fire, what is the internal pressure of the gas when its temperature reaches 927°C?
= 4 atm
P1 = P2
1 atm = P2
T1
T2
300K
1200K
7. 5.2 L of a gas is at STP. Find the new volume when the temperature rises to 38°C and the
pressure drops to 600 mmHg.
P1V1 = P2V2
T1
T2
P1V1 T2 = P2V2 T1
V2 = P1V1 T2
P2T1
Solve for the variable
solve
V2 = 7.5L
8. Pressure and volume of a gas at constant temperature are __directly____ proportional.
Which scientist said this? ___Boyle_________
9. Volume and temperature of a gas at constant pressure are ___ directly ______ proportional.
Which scientist said this? _ Charles __________
10. Volume and number of gas particles at constant pressure and temperature are ___ directly
______ proportional. Avagadro
11. If two containers are at the same temperature and pressure and their volumes are equal, they
must contain the same _________# of particles____. Which scientist said this?
________Avagadro______
12. Which travels faster CO2 or O2? How much faster? O2, it travels 1.17x faster
44.01g / mol
 O2travels1.17timesFasterThanCO2
16.00 g / mol
Gas A is faster so we know it is lighter. The lighter molar mass goes on the denominator so that rate comparison is >1
13. Gas A travels 4 times faster than Gas B. If the molar mass of Gas B is 80 g/mole, find the
molar mass of Gas A.
80 g / mol
4
Xg / mol
square both sides. 80/X=16 X=80/16
X=5 g/mol
14. a. 100°C
b. gas
c. vaporization
15. Ethylen glycol
16. At 1.0 atm , 0.75g of gas dissolves in 1L at 55 degrees. How much of the gas will dissolve in
1L at
4.0 atm at the same temperature? Who came up with this law?___Henry_______
S1
P1
17.
=
S2
P2
0.75g/L
1 atm
=
X
4 atm
= 3g/L
What volume of 3.70 M solution can be prepared using 89.5 grams of sulfuric acid?
89.5 g H2SO4 x 1 mole H2SO4 = moles
98 g H2SO4
3.70M = 0.913moles H2SO4
X L solution
=0.246L
18. What mass of magnesium chloride is required to prepare 2.15 liters of 6.50 M solution?
6.50M = X moles MgCl2
2.15 L solution
X = 14.0 moles MgCl2
14.0mole x 95.31g MgCl2
1 mole MgCl2
=
1330g (SF)
19. How would you prepare 2250. mL of a 3.250 M solution from a 16.00 M HNO3 stock solution?
M1V1 = M2V2
(16.00 M)(X mL) = (3.250 M)( 2250. mL) dilution!!!!!!!!!!!
Take 457.0mL of the stock solution (stronger) and add 1793 mL of water
20. If you mixed the following solutions, what would be the resulting molarity?
525 mL of 2.1M HCl
Molarity x Volume(L) = moles
375 mL of 4.8 M HCl
5.1 moles HCl (total) = 4.3M
295 mL of 7.6 M HCl
(2.1M)(0.525L) = 1.1 moles HCl
1.195L (total)
1195ml
(4.8M)(0.375L) = 1.8moles HCl
(7.6M)(0.295L) = 2.2moles HCl
5.1moles total
21. Circle all solutes that an “i” factor of 1?
a. C6H12O6
b. CF4
c. NH4Cl (i=2)
d. NH3
22. Why is calcium chloride more effective as rock salt in the winter than sodium chloride?
(HINT: what is the “i” factor for each?) calcium chloride (CaCl2) has an i of 3. NaCl has an i
of 2. Calcium chloride will lower the freezing point of water more.