1.
1.7 g of NaNO3 (Mr = 85) is dissolved in water to prepare 0.20 dm3 of solution. What is
the concentration of the resulting solution in mol dm–3?
2.
How many molecules are present in a drop of ethanol, C2H5OH, of mass 2.3 × 10–3 g?
(L = 6.0 × 1023 mol–1)
3.
The relative molecular mass of a gas is 56 and its empirical formula is CH2. What is the
molecular formula of the gas?
4.
How do the bond angles in CH4, NH3 and H2O compare?
5.
When 100 cm3 of 1.0 mol dm–3 HCl is mixed with 100 cm3 of 1.0 mol dm–3 NaOH, the
temperature of the resulting solution increases by 5.0 °C. What will be the temperature
change, in °C, when 50 cm3 of these two solutions are mixed?
6.
What is the total number of hydrogen atoms in 1.0 mol of benzamide, C6H5CONH2?
7.
A fixed mass of gas has a certain volume at a temperature of 50 °C. What temperature is
required to double its volume while keeping the pressure constant?
8.
Values for the successive ionization energies for an unknown element are given in the
table below.
First ionization
energy / kJ mol–1
Second ionization
energy / kJ mol–1
Third ionization
energy / kJ mol–1
Fourth ionization
energy / kJ mol–1
420
3600
4400
5900
In which group of the periodic table would the unknown element be found?
9.
Which metal nitrate solution is coloured?
A.
Zn (NO3)2(aq)
B.
Ni (NO3)2(aq)
C.
Mg (NO3)2(aq)
D.
Sc (NO3)3(aq)
10.
Which property decreases down group 7 in the periodic table?
11.
Consider the relative abundance of the isotopes of element X.
Isotope
Relative abundance (%)
24
80
25
10
26
10
X
X
X
What is the relative atomic mass of X?
12.
What is the concentration of NaCl, in mol dm–3, when 10.0 cm3 of 0.200 mol dm–3 NaCl
solution is added to 30.0 cm3 of 0.600 mol dm–3 NaCl solution?
13.
Which molecule has a non-bonding (lone) pair of electrons on the central atom?
14.
A.
BF3
B.
SO2
C.
CO2
D.
SiF4
Chloroethene, C2H3Cl, reacts with oxygen according to the equation below.
2C2H3Cl(g) + 5O2(g) → 4CO2(g) + 2H2O(g) + 2HCl(g)
What is the amount, in mol, of H2O produced when 10.0 mol of C2H3Cl and 10.0 mol of
O2 are mixed together, and the above reaction goes to completion?
15.
Consider the following reactions.
1
O2(g) → 2CuO(s)
2
Cu2O(s) → Cu(s) + CuO(s)
Cu2O(s) +
∆HO = –144 kJ
∆HO = +11 kJ
What is the value of ∆HO, in kJ, for this reaction?
Cu(s) +
1
O2(g) → CuO(s)
2
16.
A piece of metallic aluminium with a mass of 10.044 g was found to have a volume of
3.70 cm3.
A student carried out the following calculation to determine the density.
Density (g cm–3) =
10.044
3.70
What is the best value the student could report for the density of aluminium?
17.
What is the electron configuration of vanadium?
18.
How many σ and π bonds are present in a molecule of propyne, CH3CCH?
19.
The Lewis structure of SO2 is given below.
.. ..
: O ―S
..
O:
..
What is the shape of the SO2 molecule?
20.
When hydrogen peroxide decomposes, the temperature of the reaction mixture increases.
2H2O2(aq) → O2(g) + 2H2O(l)
What are the signs of ∆H, ∆S and ∆G for this reaction?