Chemistry — 2002
WASSCE · 52 questions · Answers included
52 questions
If the relative molecular mass of an element is not a whole number, it can be deduced that the element is
The atomic number of chlorine is 17. What is the number of electrons in a chloride ion?
Consider the following equation; Cr 2 O 7(aq) 2- + 14H + (aq) + 6e - → 2Cr 3+ (aq) + 7H 2 O (I) . The oxidation number of chromium changes from
Which of the following ions require the largest quantity of electricity for discharge at an electrode?
If two metallic ions of the same concentration migrate to a graphite cathode, the one that would be preferentially discharged is the one that has the
When concentrated sodium chloride solution is electrolysed using inert electrodes the products are?
Which of the following processes takes place during the production of margarine from vegetable oils?
Which of the following compounds can be represented by the molecular formula C 2 H 6 O?
When alkynes are hydrogenated completely, they produce compounds with the general molecular formula
The following compounds are hydrocarbons except
Which of the following statements about soapless detergents is correct? They
If the relative molecular mass of an element is not a whole number, it can be deduced that the element is
The atom of an element X is represented as \(^y_z X\). The basic chemical properties of X depend on the value of
The atomic number of chlorine is 17. What is the number of electrons in a chloride ion?
A hydrogen atom which has lost an electron contains
Which of the following elements has a ground state electronic configuration with an incomplete penultimate shell?
The conclusion from Rutherford's alpha-scattering experiment is that
An element Y has the electronic configuration 1s 2 2s 2 2p 6 6 2 3p 4 . To what period does it belong in the periodic table?
If a metal R forms a compound with the formula R(NO 3 ) 2 , the formula of its tetraoxosulphate (IV) is
Which of the following decreases when a given mass of gas is compressed to half its initial volume?
What volume of hydrogen will be produced if 100cm 3 of ammonia is completely decomposed at constant temperature and pressure? The equation for reaction is 2NH 3(g) → N 2(g) + 3H 2(g)
Calculate the mass of chlorine gas which occupies a volume of 1.12 dm\(^3\) a volume of 1.12 dm\(^3\) at s.t.p [Cl = 35.5, 1 mole og gas occupies 22.4 dm\(^3\) at s. t. p ]
Determine the mass of sulphur (IV) oxide obtained when 91.0g of oxygen reacts completely with sulphur according to the following equation: S(s) + O\(_2\)(g) → SO\(_2\)(g) [S = 32; O = 16]
The gas given off when NH4 Cl is heated with an alkali is
A major factor considered in selecting a suitable method for preparing a simple salt is its
Which of following acids forms normal salts only?
A substance is said to be hygroscopic if it absorbs
Which of the following substances increases in mass when heated in air?
Calculate the mass of sodium hydroxide in 5.00 dm 3 of a 0.125 mol dm -3 solution. [NaOH = 40 g mol -1 ]
Which of the following salt solutions will have a pH greater than 7?
What will happen if more heat is applied to the following system at equilibrium? X\(_2\)(g) + 3Y\(_2\)(g) ⇌ 2XY\(_3\)(g); ∆H = xKJmol\(^{-1}\)
What is the expression for the equilibrium constant (K c ) for the following reaction? N 2(g) + O 2(g) ⇌ 2NO (g)
Equal amounts of marble chips are reacted separately with 100cm3 of hydrochloric acid of different concentrations. If all the marble chips reacted; which of the following remained the same in each case?
CuSO 4 5H 2 O can be obtained from an aqueous solution of copper (ll) tetraoxosulphate (VI) by
Which of the following compounds will leave a metal residue when heated?
A visible change is observed when a strip of iron is placed in an aqueous solution of
Consider the following equation: Cr\(_2\)O\(_7\)\(^{2-}\)(aq) + 14H\(^+\)(aq) + 6e\(^-\) → 2Cr\(^{3+}\)(ag) + 7H\(_2\)O(1). The oxidation number of chromium changes from
Which of the following ions require the largest quantity of electricity for discharge at an electrode?
If two metallic ions of the same concentration migrate to a graphite cathode, the one that would be preferentially discharged is the one that has the
When concentrated sodium chloride solution is electrolysed using inert electrodes, the products are
Which of the following processes takes place during the production of margarine from vegetable oils?
Which of the following compounds can be represented by the molecular formula C 2 H 6 O?
When alkynes are hydrogenated completely they produce compounds with the general molecular formula
The following compounds are hydrocarbons except
The reaction between ethene and chlorine to form 1, 2-dichloroethane is
Which of the following statements about soapless detergents is correct? They
Which of the following types of alkanols undergo oxidation to produce alkanoic acids? I. Primary alkanols II. Secondary alkanols III. Tertiary alkanols
A suitable reagent for distinguishing between ethanoic acid ethanol is
The reaction of sucrose with dilute HCI produces
The energy value of petrol can be determined by a
Iron is often galvanized in order to
One of the methods used for combating air pollution is