If the relative molecular mass of an element is not a whole number, it can be deduced that the element is
Trả lời
(D)
an isotopic mixture
2
The atomic number of chlorine is 17. What is the number of electrons in a chloride ion?
Trả lời
(C)
18
3
Consider the following equation; Cr2O7(aq)2- + 14H+(aq) + 6e- → 2Cr3+(aq) + 7H2O(I). The oxidation number of chromium changes from
Trả lời
(C)
+ 6 to + 3
4
Which of the following ions require the largest quantity of electricity for discharge at an electrode?
Trả lời
(A)
2.0 mole of Q 3+
5
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
Trả lời
(D)
stronger tendency to accept electrons
6
When concentrated sodium chloride solution is electrolysed using inert electrodes the products are?
Trả lời
(D)
soduim hydroxide, hydrogen and chlorine
7
Which of the following processes takes place during the production of margarine from vegetable oils?
Trả lời
(C)
Hydrogenation
8
Which of the following compounds can be represented by the molecular formula C2H6O?
Trả lời
(B)
Ethanol
9
When alkynes are hydrogenated completely, they produce compounds with the general molecular formula
Trả lời
(B)
C nH 2n+2
10
The following compounds are hydrocarbons except
Trả lời
(A)
methylpropanoate
11
Which of the following statements about soapless detergents is correct? They
Trả lời
(A)
lather readily with hard water
12
If the relative molecular mass of an element is not a whole number, it can be deduced that the element is
Trả lời
(D)
an isotopic mixture
13
The atom of an element X is represented as \(^y_z X\). The basic chemical properties of X depend on the value of
Trả lời
(B)
Z
14
The atomic number of chlorine is 17. What is the number of electrons in a chloride ion?
Trả lời
(C)
18
15
A hydrogen atom which has lost an electron contains
Trả lời
(A)
one proton only
16
Which of the following elements has a ground state electronic configuration with an incomplete penultimate shell?
Trả lời
(A)
Iron
17
The conclusion from Rutherford's alpha-scattering experiment is that
Trả lời
(A)
atoms are mostly empty space with a small nucleus
18
An element Y has the electronic configuration 1s22s22p6623p4. To what period does it belong in the periodic table?
Trả lời
(A)
3
19
If a metal R forms a compound with the formula R(NO3)2 , the formula of its tetraoxosulphate (IV) is
Trả lời
(B)
RSO4
20
Which of the following decreases when a given mass of gas is compressed to half its initial volume?
Trả lời
(A)
Average intermolecular distance
21
What volume of hydrogen will be produced if 100cm3 of ammonia is completely decomposed at constant temperature and pressure? The equation for reaction is 2NH3(g) → N2(g) + 3H2(g)
Trả lời
(B)
150cm3
22
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 ]
Trả lời
(B)
3.55g
23
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]
Trả lời
(D)
182g
24
The gas given off when NH4 Cl is heated with an alkali is
Trả lời
(D)
NH3
25
A major factor considered in selecting a suitable method for preparing a simple salt is its
Trả lời
(D)
solubility in water
26
Which of following acids forms normal salts only?
Trả lời
(C)
Acetic acid
27
A substance is said to be hygroscopic if it absorbs
Trả lời
(D)
moisture from the atmosphere without dissolving
28
Which of the following substances increases in mass when heated in air?
Trả lời
(C)
Magnesium ribbon
29
Calculate the mass of sodium hydroxide in 5.00 dm3 of a 0.125 mol dm-3 solution. [NaOH = 40 g mol-1]
Trả lời
(D)
25.0 g
30
Which of the following salt solutions will have a pH greater than 7?
Trả lời
(B)
Na2CO3(aq)
31
What will happen if more heat is applied to the following system at equilibrium?
What is the expression for the equilibrium constant (Kc) for the following reaction? N2(g) + O2(g) ⇌ 2NO(g)
Trả lời
(D)
\(\frac{[NO]^2}{[N_2][O^2]}\)
33
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?
Trả lời
(B)
Total mass of gas evolved during the reaction
34
CuSO45H2O can be obtained from an aqueous solution of copper (ll) tetraoxosulphate (VI) by
Trả lời
(D)
crystallization
35
Which of the following compounds will leave a metal residue when heated?
Trả lời
(B)
AgNO3
36
A visible change is observed when a strip of iron is placed in an aqueous solution of
Trả lời
(C)
CuSO4
37
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
Trả lời
(C)
+6 to +3
38
Which of the following ions require the largest quantity of electricity for discharge at an electrode?
Trả lời
(A)
2.0 mole of Q 3+
39
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
Trả lời
(D)
stronger tendency to accept electrons
40
When concentrated sodium chloride solution is electrolysed using inert electrodes, the products are
Trả lời
(B)
hydrogen and chlorine
41
Which of the following processes takes place during the production of margarine from vegetable oils?
Trả lời
(C)
Hydrogenation
42
Which of the following compounds can be represented by the molecular formula C2H6O?
Trả lời
(B)
Ethanol
43
When alkynes are hydrogenated completely they produce compounds with the general molecular formula
Trả lời
(C)
CnH2n+2
44
The following compounds are hydrocarbons except
Trả lời
(A)
methylpropanoate
45
The reaction between ethene and chlorine to form 1, 2-dichloroethane is
Trả lời
(C)
addition
46
Which of the following statements about soapless detergents is correct? They
Trả lời
(A)
lather readily with hard water
47
Which of the following types of alkanols undergo oxidation to produce alkanoic acids? I. Primary alkanols II. Secondary alkanols III. Tertiary alkanols
Trả lời
(D)
l only
48
A suitable reagent for distinguishing between ethanoic acid ethanol is
