Chemistry — 2012
WASSCE · 44 questions · Answers included
44 questions
The number of orbitals in a p-sub level of an atom is
Which of the following electron configurations represents that of an atom in its ground state?
Which of the following ions has an electron configuration different from the other?
The atomic radii of metals are usually
Two elements, X and Y are in the same group on the periodic table because they both have the same
The d-block elements are paramagnetic because they
Which of the following statements about a radioactive substance is/are correct? l. lt emits radiation continuously and spontaneously. ll. The emitted radiations are affected by temperature and pressure III. The radiation can penetrate opaque matter
Which of the following elements is a metalloid?
Which of the following halogens is liquid at room temperature?
The shape of a graphite crystal is
The complex compound formed by the combination of two elements with a large electronegativity difference is likely to be
The complex compound formed when aluminum dissolves in aqueous sodium hydroxide is
The vapour pressure of a liquid depends on l. temperature. ll. rate of condensation. III. cohesive forces holding the particles together
MgO does not readily dissolve in water because
Consider the following reaction equation: CaCO\(_{3(s)}\) + 2HCI\(_{(aq)}\) → CaCl\(_{2(aq)}\) + H\(_2\)O\(_{(l)}\) + CO\(_{2(g)}\). What mass of CaCI\(_2\) would be obtained when 25.0g of CaCO\(_{3(s)}\) is reacted with excess HCI\(_{(aq)}\)? [CaCO\(_3 = 100; CaCI\(_2\) = 111]
The number of sulphur atoms in 3.20g of SO\(_{2(g)}\) is [O = 16.0;S = 32.0; Avogadro constant = 6.02 x 10\(^{23}\)]
Consider the reaction represented by the following equation: xCH\(_3\)OH + yO\(_2\) → 2CO\(_2\) + zH\(_2\)O. The values of x,y and z respectively, are
The formula of mercury (l) dioxonitrate (III) is
A sample of a gas may be identified as chlorine if it turns
A metal M forms two types of chlorine, MCl\(_2\) and MCl\(_3\) which of the following laws best explains the relationship between the chlorides? Law of
Which of the following metals would readily displace hydrogen from steam?
The volume occupied by 0.4 g of hydrogen gas at s.t.p. is [H = 1. 00; Molar volume at s.t.p. = 22.4 dm3]
When a substance changes directly from the solid state to the gaseous state without forming a liquid, the substance is said to
At ordinary temperature H\(_2\)O is a liquid while H\(_2\)S is a gas. This is because H\(_2\)O has
The postulate that molecules are in constant random motion best explains why liquids
Which of the following gases has the lowest rate of diffusion under the same condition? [H = 1.00; He = 4. 00; O = 16.0; CI = 35.5]
The energy evolved when magnesium burns in air is in the form of
A substance L reacts with NH\(_4\)NO\(_{3(aq)}\) to generate ammonia gas. L is likely to be
On heating, the following trioxocarbonate (IV) salts decompose to give solid residue except
Which of the following pH values indicates that a solution is a strong base?
The hydrolysis of NH\(_4\)CI gives
A spot of oil paint on a shirt can best be removed using?
Consider the reaction represented by the following equation: CuO\(_{(s)}\) + H\(_2\)SO\(_{4(aq)}\) → CuSO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\). Which of the following factors will not affect the rate of the reaction?
Which of the following devices function on redox reaction? l. Dry cell ll. Car battery III. Electric generator
The oxidation number of Fe in [Fe(CN)\(_6\)]\(^{3-}\) is
Consider the following reaction equation: C\(_{16}\)H\(_{34}\) → C\(_5\)H\(_{12}\) + C\(_{11}\)H\(_{22}\). The process represented by the equation is
Which of the following substances would not produce ethanol when fermented?
An alkanol can be prepared by the reaction of an alkene with
A tertiary alkanol has a molecular formula C\(_4\)H\(_{10}\)O. What is the structural formula of the compound?
Which of the following industrial processes depends on the action of enzymes?
Which of the following pollutants is not usually recycled?
A metal that is widely used in the manufacture of paints and overhead electric cables is
Brass is a mixture of
Which of the following substances is mainly responsible for the depletion of the ozone layer?