Y12 TEST: Quantitative Chemistry
04.11.10
1. What amount of oxygen, O2, (in moles) contains 1.8×1022 molecules?
A. 0.0030
B. 0.030
C. 0.30
D. 3.0
ANSWER
(Total 1 mark)
2. Which compound has the empirical formula with the greatest mass?
A. C2H6
B. C4H10
C. C5H10
D. C6H6
ANSWER
(Total 1 mark)
3. 3.0 dm3 of sulfur dioxide is reacted with 2.0 dm3 of oxygen according to the equation below.
2SO2(g) + O2(g) → 2SO3(g)
What volume of sulfur trioxide (in dm3) is formed? (Assume the reaction goes to completion and all gases are measured at the same temperature and pressure.)
A. 5.0
B. 4.0
C. 3.0
D. 2.0
ANSWER
(Total 1 mark)
4. What amount (in moles) is present in 2.0 g of sodium hydroxide, NaOH?
A. 0.050
B. 0.10
C. 20
D. 80
ANSWER
(Total 1 mark)
5. Which change in conditions would increase the volume of a fixed mass of gas?
|
|
Pressure /kPa |
Temperature /K |
|
A. |
Doubled |
Doubled |
|
B. |
Halved |
Halved |
|
C. |
Doubled |
Halved |
|
D. |
Halved |
Doubled |
ANSWER
(Total 1 mark)
6. What volume of 0.500 mol dm–3 HCl(aq) is required to react completely with 10.0 g of calcium carbonate according to the equation below?
CaCO3(s) + 2HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g)
A. 100 cm3
B. 200 cm3
C. 300 cm3
D. 400 cm3
ANSWER
(Total 1 mark)
7. An organic compound, A, containing only the elements carbon, hydrogen and oxygen was analysed.
(a) A was found to contain 54.5% C and 9.1% H by mass, the remainder being oxygen. Determine the empirical formula of the compound.
ANSWER
(3)
(b) A 0.230 g sample of A, when vaporized, had a volume of 0.0785 dm3 at 95°C and 102 kPa. Determine the relative molecular mass of A.
ANSWER
(3)
(c) Determine the molecular formula of A using your answers from parts (a) and (b).
ANSWER
(1)
(Total 7 marks)
„ è8. The temperature in Kelvin of 1.0 dm3 of an ideal gas is doubled and its pressure is tripled. What is the final volume of the gas in dm3?
A. 
B. 
C. 
D. 
ANSWER
(Total 1 mark)
9. (i) Crocetin consists of the elements carbon, hydrogen and oxygen. Determine the empirical formula of crocetin, if 1.00 g of crocetin forms 2.68 g of carbon dioxide and 0.657 g of water when it undergoes complete combustion.
ANSWER
(6)
(ii) Determine the molecular formula of crocetin given that 0.300 mole of crocetin has a mass of 98.5 g
ANSWER
(2)
(Total 8 marks)
10. How many hydrogen atoms are in one mole of ethanol, C2H5OH?
A. 1.00×1023
B. 3.61×1024
C. 5.00
D. 6.00
(Total 1 mark)
11. Which aqueous solution contains the most hydrogen ions?
A. 20 cm3 of 2 mol dm–3 sulfuric acid
B. 10 cm3 of 4 mol dm–3 nitric acid
C. 80 cm3 of 0.5 mol dm–3 hydrochloric acid
D. 40 cm3 of 0.5 mol dm–3 sulfuric acid
ANSWER
(Total 1 mark)
12. 0.502 g of an alkali metal sulfate is dissolved in water and excess barium chloride solution, BaCl2(aq) is added to precipitate all the sulfate ions as barium sulfate, BaSO4(s). The precipitate is filtered and dried and weighs 0.672 g.
(a) Calculate the amount (in mol) of barium sulfate formed.
ANSWER
(2)
(b) Determine the amount (in mol) of the alkali metal sulfate present.
ANSWER
(1)
(c) Determine the molar mass of the alkali metal sulfate and state its units.
ANSWER
(2)
(d) Deduce the identity of the alkali metal, showing your workings.
ANSWER
(2)
(e) Write an equation for the precipitation reaction, including state symbols.
ANSWER
(2)
(Total 9 marks)