Worksheet 1 for grade 12 on unit 1(Solution)
1. Which of the following is not a solution?
A) Sea water
2.
B)
Carbonated water
C) benzene
D)
Brass
In
which
of
the
following
phases
can
a
solution
be
made?
A. Solid and liquid phases only
B. Gas and solid phases only
C. Liquid and gas phases only
D. Solid, liquid and gas phase
3. Which one of the following solution is not solid-solid solution?
A.Bronze
B.Brass
C.Solder
D.Salt solution
4. The solubility of K2Cr2O7in water is 125 g/L at 20 0C. A solution is prepared at 20 0C that
contains 6.25 grams of K2Cr2O7in 50 mL of water. This solution is
(A) Diluted. (B) Unsaturated. (C) Supersaturated. (D) Saturated
5. What is the concentration of O2(g), in parts per million, in a solution that contains 0.008 gram
of
O2(g) dissolved
in
1000.
grams
of
H2O(l)?
(1) 0.8 ppm
(2) 80 ppm
(3) 8 ppm
(4) 800 ppm
6. What is the molarity of sodium chloride in solution that is 13.0% by mass sodium chloride and
that
has
a
density
of
1.10
g/mL?
A) 2.23
B) 143
C) 2.45
D) 2.56
7. Commercial concentrated sulfuric acid(density=1.831g/cm3) is 94.0% H2SO4,by mass.What is
the normality of H2SO4 solution?Molar mass of H2SO4 solution=98g/mol)
A. 16.8M
B. 28.2
C. 35 N
D. 40.4M
8.Calculate the molality of a solution that contains 51.2 g of naphthalene, C10H8, in 500 mL of
carbon tetrachloride. The density of CCl4 is 1.60 g/mL.
(a) 0.250 m (b) 0.500 m (c) 0.750 m (d) 0.840 m (e) 1.69 m
9.What is the vapor pressure of a solution of 50.0 g of CCl4 and 50.0 g of CHCl3 at 25˚C. The
vapor pressures at 25˚C for pure CCl4 and CHCl3 are 98.3 torr and 172.0 torr
respectively.MWCHCl3=119.37gm/mol
and
MW
CCl4=
153.81gm/mol
a) 131 torr b) 140. Torr c) 149 torr d) 126 torr e) None of the Above
10. What is the mole fraction of a solute in one molal aqueous solution?
A.0.009
B.0.018
C.0.027
D.0.036
11. A solution of 0.640 g of azulene in 100.0 g of benzene boils at 80.230˚C. The boiling point of
benzene is 80.100˚C; the Kb is 2.53 0c/m·. What is the molecular weight of azulene?
Helpful
Information:
The
van’t
Hoff
factor
is
1
for
azulene.
a) 108
b) 117
c) 134
d) 99
12. What is the freezing point of a solution of 250 g of CaCl2 in 1Kg of water?(kf for
H2O=1.86Kg/mol
A. -1.3 °C
B. -6.5 °C
C. -9.0 °C
D. -13°C
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13. An aqueous solution is 70.0% nitric acid (HNO3) by mass. What is the concentration of
HNO3 expressed in molality?
A. 0.559
B. 8.62m
C. 11.1m
D. 37.0m
14. A solution was prepared by dissolving 3.75 g of pure hydrocarbon in 95.0 g of cyclohexane.
The boiling point of pure cyclohexane was observed to be 80.70°C and that of the solution was
81.45°C. What is the approximate molecular weight of the hydrocarbon? (kb for cyclohexane =
2.79°C/m)
A. 71.0 g/mol
B. 105 g/mol
C. 147 g/mol
D. 312 g/mol
15. What is the net ionic equation for the reaction of NaOH(aq) and H2SO4(aq)?
A. 2NaOH (aq)
+ H2SO4 (aq)
Na2SO4 (aq) + H2O(l)
B.2Na+ (aq) + 2OH-(aq) + 2H+(aq) + SO42-(aq)
C.H+(aq)
D.2H+(aq)
+ OH-(aq)
+ 2OH-(aq)
2Na+(aq) + SO42-(aq) +2H2O(l)
H2O(l)
2H2O(l)
16. How many milliliter of water is required to dilute 50ml of 3.5M H2SO4 to 2.0M H2SO4?
A.87.5
B. 37.5
C.45
D.75
17. What volume of 0.1M glucose, C6H12O6 contains 12.04x1022g molecules of glucose?
A.0.2L
B.0.4L
C. 2L
D. 1L
18. Which of the following units is useful in relating concentration of solution with its vapour
pressure? (A) mole fraction (B) parts per million (C) mass percentage (D) molality
19. Which observation(s) reflect(s) colligative properties?
(I) A 0.5 m NaBr solution has a higher vapor pressure than a 0.5 m BaCl2 solution.
(II) A 0.5 m NaOH solution freezes at a lower temperature than pure water.
(III) Pure water freezes at a higher temperature than pure methanol.
(a) only I (b) only II (c) only III (d) I and II (e) I and III
20. The vapor pressure of pure water at 85oC is 434 torr. What is the vapor pressure at 85oC of a
solution prepared from 100 mL of water (density 1.00 g/mL) and 150 g of diglyme, C 6H14O3, a
nonvolatile substance?
(a) 361 torr
(b) 390 torr
(c) 425 torr
(d) 388 torr
(e) 317 torr
21. Which observation(s) reflect(s) colligative properties?
(I) A 0.5 m NaBr solution has a higher vapor pressure than a 0.5 m BaCl2 solution.
(II) A 0.5 m NaOH solution freezes at a lower temperature than pure water.
(III) Pure water freezes at a higher temperature than pure methanol.
(a) only I (b) only II
(c) only III
(d) I and II
(e) I and III
2
22. If 4.27 grams of sucrose, C12H22O11, are dissolved in 15.2 grams of water, what will be the
boiling point of the resulting solution? (Kb for water = 0.512 oC/m) .
(a) 101.64 oC (b) 100.43 oC (c) 99.626 oC (d) 100.73 oC (e) 101.42 oC
23. Calculate the approximate initial boiling point (in oC) of a solution of 285 g of magnesium
chloride in 2.0 kg of water. (Assume complete dissociation of the salt.)
(a) 103.1 oC (b) 101.6 oC (c) 102.3 oC
(d) 100.8 oC
(e) 104.8 oC
24.A solution made by dissolving 9.81 g of a nonvolatile nonelectrolyte in 90.0 g of water boiled
at 100.37 oC at 760 mm Hg. What is the approximate molecular weight of the substance? (For
water, Kb = 0.51 oC/m)
(a) 240 g/mol (b) 150 g/mol
(c) 79 g/mol
(d) 61 g/mol
(e) 34 g/mol
25. What is the freezing point of an aqueous 1.00 m NaCl solution? (Kf = 1.86 oC/m) (Assume
complete dissociation of the salt.)
(a) -1.86 oC
(b) +1.86 oC
(c) -3.72 oC
(d) -0.93 oC
(e) 0.0 oC
26. A 17.3 mg sample of an organic compound (a non-electrolyte) was ground up with 420 mg
of camphor to form a homogeneous mixture melting at 170.0 oC. What is the apparent formula
weight of the organic compound? (Kf of camphor = 37.7 oC/m, m.p. of camphor = 178.4 oC)
(Note: This is a freezing point depression problem - note the Kf of camphor - camphor is the
solvent.)
(a) 353 g/mol (b) 285 g/mol
(c) 231 g/mol
(d) 185 g/mol
(e) 166 g/mol
27. Calculate the osmotic pressure associated with 50.0 g of an enzyme of molecular weight
98,000 g/mol dissolved in water to give 2500 mL of solution at 30.0 oC.
(a) 0.05 torr (b) 1.5 torr (c) 1.96 torr
(d) 2.48 torr
(e) 3.71 torr
27. A 250 mL solution containing 21.4 g of a polymer in toluene had an osmotic pressure of
0.055 atm at 27 oC. What is the apparent formula weight of the polymer?
(a) 15,000 g/mol (b) 18,000 g/mol (c) 26,000 g/mol
(d) 32,000 g/mol
(e) 38,000 g/mol
28. A solution containing 10.0 g of an unknown liquid and 90.0 g water has a freezing point of 3.33℃. Given Kf = 1.86 oC/m for water, the molar mass of the unknown liquid is g/mol.
A) 161 B) 69.0 C) 62.1 D) 333
29. . Which of the following aqueous solutions will have the highest boiling point?
A) 0.10 m NaCl B) 0.10 m Na2SO4 C) 0.20 m glucose D) 0.25 m sucrose E) 0.10 m SrSO4
30 . The boiling point of Benzene, Ethanol, Octane and Pentane are 80°C, 78°C, 126°C and 36°C
respectively. Which of the following will show highest vapor pressure at room temperature?
A) Benzene.
B) Octane.
C) Pentane.
D) Ethanol.
31. What are the ideal van't Hoff factors for the following compounds?
Ba(OH)2, C6H12O6, K3PO4, HNO3 ?
(a) 1, 1, 1, 1
(b) 2, 1, 2, 2
(c) 3, 1, 4, 2
(d) 6, 3, 5, 5
3
II. Give short answer
1. Suggest the most important type of intermolecular attractive interaction in the following pairs.
(i) n-hexane and n-octane
(ii) I2 and CCl4
(iii) NaClO4 and water
(iv) methanol and acetone (v) acetonitrile (CH3CN) and acetone (C3H6O).
2. What is the boiling point of an aqueous sugar solution that freezes at -7.98OC at standared
condition (Kf= 1.86OC/molal and (Kb= o.52OC/molal )
3.If you prepare a solution by dissolving 4 gm of NaOH in 250 gm of water
A) What is the molality of the solution? B) at what temperature would the solution boil at
standard condition (Given molar mass of NaOH =40gm/mol and water = 18 gm/mol ) (K b=
o.52OC/ molal )
4. How many grams of CaCl2 are needed to prepare 250.0 mL of 0.150 M CaCl2 (MM =
111g/mol)?
5. What is the concentration of a solution prepared by diluting 45.0 mL of 8.25 M HNO3 to 135.0
mL?
4