aa [18 marks]
1.
[Maximum mark: 1]
How many oxygen atoms are present in 0.0500 mol Ba(OH)2•8H2O?
22N.1.sl.TZ0.1
NA = 6.02 × 1023
A. 3.01 × 1023
B. 6.02 × 1023
C. 3.01 × 1024
D. 6.02 × 1024
2.
[Maximum mark: 1]
What is the change of state for a gas to a solid?
[1]
22N.1.sl.TZ0.2
A. Condensation
B. Deposition
C. Freezing
D. Sublimation
[1]
3.
[Maximum mark: 1]
Which is a possible empirical formula for a substance with Mr = 42?
22N.1.sl.TZ0.4
A. CH
B. CH2
C. C3H6
D. C3H8
4.
[Maximum mark: 1]
What is the molecular formula of a compound with an empirical
formula of CHO2 and a relative molecular mass of 90?
[1]
22M.1.sl.TZ1.3
A. CHO2
B. C2H2O4
C. C3H6O3
D. C4H10O2
5.
[Maximum mark: 1]
8.8 g of an oxide of nitrogen contains 3.2 g of oxygen. What is the
empirical formula of the compound?
[1]
22M.1.sl.TZ1.4
A. N2O5
B. N2O
C. NO2
D. NO
[1]
6.
[Maximum mark: 1]
Which equation represents the deposition of iodine?
22M.1.sl.TZ2.4
A. I2 (g) → I2 (l)
B. I2 (g) → I2 (s)
C. I2 (l) → I2 (g)
D. I2 (s) → I2 (g)
7.
[Maximum mark: 1]
What is the number of hydrogen atoms in 2.00 moles of Ca(HCO3)2?
[1]
21N.1.sl.TZ0.1
Avogadro’s constant, L or NA: 6.02 × 1023 mol−1
A. 2.00
B. 4.00
C. 1.20 × 1024
D. 2.41 × 1024
[1]
8.
[Maximum mark: 1]
Which statement describes all homogeneous mixtures?
21N.1.sl.TZ0.2
A. Any sample has the same ratio of the components.
B. The components are covalently bonded together.
C. The components cannot be easily separated.
D. The mixture needs a specific ratio of components to form.
9.
[Maximum mark: 1]
How much ethanol contains 1.20 × 1024 atoms of carbon?
[1]
21N.1.hl.TZ0.1
Avogadro’s constant, L or NA: 6.02 × 1023 mol−1
A. 0.333 mol
B. 0.500 mol
C. 1.00 mol
D. 2.00 mol
[1]
10.
[Maximum mark: 1]
Which molecule has the same empirical formula as molecular formula?
21M.1.sl.TZ2.3
A. CH3COOH
B. C2H5OH
C. C2H4
D. C4H10
11.
[Maximum mark: 1]
A sample of a compound contains approximately 24.0 g C, 3.0 g H, and
1.6 g O. What is the empirical formula of the compound?
[1]
21M.1.hl.TZ1.2
A. C20H30O
B. C84H10O6
C. C2H3O
D. C24H30O2
12.
[Maximum mark: 2]
Ammonium nitrate, NH4NO3, is used as a high nitrogen fertilizer.
(a)
[1]
22N.2.hl.TZ0.1
Calculate the percentage by mass of nitrogen in ammonium
nitrate. Use section 6 of the data booklet.
[1]
Solid ammonium nitrate can decompose to gaseous dinitrogen monoxide and
liquid water.
(b)
Write the chemical equation for this decomposition.
[1]
13.
[Maximum mark: 2]
22M.2.sl.TZ1.1
When heated in air, magnesium ribbon reacts with oxygen to form magnesium
oxide.
(a(i))
Write a balanced equation for the reaction that occurs.
[1]
The presence of magnesium nitride can be demonstrated by adding water to the
product. It is hydrolysed to form magnesium hydroxide and ammonia.
(a(ii)) Calculate coefficients that balance the equation for the
following reaction.
__ Mg3N2 (s) + __ H2O (l) → __ Mg(OH)2 (s) + __ NH3 (aq)
14.
[Maximum mark: 3]
Copper forms two chlorides, copper(I) chloride and copper(II) chloride.
(a(i))
[1]
19N.2.sl.TZ0.5
Solid copper(II) chloride absorbs moisture from the atmosphere
to form a hydrate of formula CuCl2• xH2O.
A student heated a sample of hydrated copper(II) chloride, in
order to determine the value of x. The following results were
obtained:
Mass of crucible = 16.221 g
Initial mass of crucible and hydrated copper(II) chloride =
18.360 g
Final mass of crucible and anhydrous copper(II) chloride =
17.917 g
Determine the value of x.
[3]
15. Analytical and spectroscopic techniques enable chemists to identify and determine structures of
compounds.
(a)
An unknown organic compound, X, comprising of only carbon, hydrogen and oxygen
was found to contain 48.6 % of carbon and 43.2 % of oxygen.
Determine the empirical formula .
[ 3]
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(b)
Determine the molecular formula of X if the molar mass of X is 74.1 g mol-1. .
[1]