Year 11 Water Practice Quiz 3 Solution
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1. Which statement is true? Multiple Choice: 1 mark each
a) Glycerine (1,2,3 propantriol) is very viscous because it contains a lot of dissolved solute.
b) Cooling honey makes it less viscous.
c) Honey is very viscous because it contains a lot of dissolved solute.
d) Warming glycerine makes it more viscous.
2. Construct Lewis dot diagrams of the following:
5 marks
3. Water has its maximum density (1.00 g/cm3) at a temperature of 4oC. What will the maximum mass of 8mL
of the water be?
1 mark
Density = mass / volume
mass = density x volume = 1.00 x 8 = 8g
(1 mL = 1 cm3)
4. Which of the following is a demonstration of water’s high surface tension?
a) The ability of some insects to walk on water.
b) The high boiling point of water compared to molecules of similar molecular weight.
c) The fact that solid water (ice) has a lower density than liquid water.
d) The polar nature of water.
5. Complete the following table for salts dissolving in water.
2 marks
Salt
ΔH (kJ/mol)
Water temperature
Process
NaOH
-44.5
increases / decreases
endothermic / exothermic
KNO3
+34.9
increases / decreases
endothermic / exothermic
6. What is the heat capacity of water?
a) 6 kJ/g.K
b) 4.18 kJ/g.K.
c) 4.18 Cal/g.K.
d) 4.18 J/g.K
7. Why does glycerine have a higher viscosity than water?
a) Glycerine molecules contain 3 oxygen atoms per molecule so have more hydrogen bonding.
b) Water is the most viscous liquid known.
c) Glycerine is sweet like honey and has a similar viscosity.
d) The water molecule is much larger than the glycerine molecule.
8. Write an ionic equation for carbon dioxide dissolving in water to form carbonic acid (H2CO3).
1 mark
CO2(g) + H2O(l) → 2H+(aq) + CO32-(aq)
9. Write a net ionic equation of the formation of the precipitate when lead (II) nitrate is mixed with ammonium
chloride. 1 mark
Pb2+(aq) + 2Cl-(aq) → PbCl2 (s)
10. Why is water’s ability to absorb heat important to life on Earth?
a) It makes water a good solvent.
b) It helps to prevent land animals from drowning.
c) It moderates temperature changes and ensures that water is present in liquid form.
d) It helps to prevent salts in seawater from precipitating out of solution.
11. Which list contains only non-polar molecules?
a) Water, ammonia, hydrogen fluoride.
b) Ammonium, water, hydrogen.
c) Cyclohexane, kerosene, carbon dioxide
d) Sodium chloride, water, potassium iodide.
12. Name three types of intermolecular forces in order of decreasing strength.

Hydrogen bonding

Dipole-dipole

Dispersion
3 marks
13. Which of the following is a solubility rule?
a) All bromides are soluble.
b) Most hydroxides are insoluble in water.
c) Most hydroxides are soluble in water.
d) All ionic substances are soluble in water.
14. Identify the main type of intermolecular forces for each of the following substances.

Glycerine (Hydrogen bonding)

Hydrogen cyanide (H-C≡N) (Dipole-dipole)

Argon (Dispersion)
3 marks
15. Viscosity in hydrocarbons increases with increasing chain length because long molecules often get tangled
when they move. Which of the following hydrocarbons is most viscous?
a) n-hexane.
b) n-decane.
c) n-heptane.
d) n-octane.
16. Which of the following substances are highly soluble in water?
a) Strontium carbonate, silver sulfate, zinc oxide.
b) Oxygen, salts, alcohols.
c) Oxygen, carbon dioxide, ammonia.
d) Ethyl alcohol, lithium hydroxide, glycerol.
17. Which statement best defines hydrogen bonding?
a) A force of repulsion between hydrogen atoms in the same molecule.
b) A force of attraction between hydrogen atoms in different molecules.
c) An force of attraction between the hydrogen atoms in a molecule and the unbonded pair of electrons
of an oxygen, nitrogen or fluorine atom of another molecule.
d) An force of attraction between the hydrogen atoms in a molecule and the unbonded pair of electrons of
an oxygen, nitrogen or fluorine atom of the same molecule.
18. What is the chemical formula of the precipitate when solutions of ammonium chloride and silver (I) acetate
are mixed?
a) AgCl.
b) KNO3.
c) NH4Cl.
d) AgCH3COOCl.
19. Write an equation for the reaction between strontium acetate and lithium sulfate solutions. Show all states.
2 marks
Sr(CH3COO)2(aq) + Li2SO4(aq) → SrSO4(s) + 2LiCH3COO (aq)
20. How is molarity defined?
a) The number of moles of solute per litre of solvent.
b) The mass of solute per litre of solution.
c) The number of moles of solvent per litre of solution.
d) The number of moles of solute per litre of solution.
21. What is the molarity of 280ml of solution containing 28g of calcium chloride?
2 marks
v=0.28L, m=28g, M=40.01+2x35.45 = 110.91
n=m/M = 28/110.91 = 0.25
c=n/v = 0.25/0.28 = 0.90M
22. How much heat is required to raise the temperature of 120g of water from 300K to 425K?
2 marks
q=mCΔT= 120 x 4.18 x (425-300) = 62700 J
23. What is the volume of 320ml of a 0.3M Ba(CH3COO)2 solution diluted to 0.12M?
C1=0.3, V1 = 0.32, C2 = 0.12, V2=?
C1V1 = C2V2 V2=C1V1/C2 = 0.3 x 0.32 / 0.12 =0.8L
2 marks
24. If one calorie is defined as the amount of heat required to raise the temperature of one gram of water by
one degree Celsius, how much heat is required to raise the temperature of 6 grams of water by 10oC in
calories and in joules?
2 marks
q=mCΔT= 6g x 1 cal/g.K x 10K = 60 cal
q=mCΔT= 6g x 4.18 J/g.K x 10K = 250.8 J
25. Which of the following gases is highly soluble in water?
a) Oxygen
b) Ammonia
c) Nitrogen
d) Carbon dioxide
26. The enthalpy of solution of anhydrous oxalic acid in water was measured in a calorimeter and found to be
endothermic. Would the value for ΔH be positive or negative?
1 mark
Positive. A positive ΔH value indicates that process is endothermic.
27. Which is more polar, HBr or HF? Why?
2 marks
HF is more polar than HBr because fluorine is more electronegative than bromine.
28. Draw lithium fluoride dissolved in water.
2 marks
29. Describe the trend in electronegativity across periods.
2 marks
Electronegativity increases across periods.
30. Describe the trend in electronegativity down groups.
2 marks
Electronegativity decreases down groups
31. Describe the electronegativity of group 8 elements.
2 marks
Group 8 elements do not form bonds so are not electronegative.
Easy way to remember electronegativity trends:
Fluorine is the most electronegative element, so elements become more electronegative as
they get closer to Fluorine in the Periodic Table.