Elements which belong to the same group in the Periodic Table are characterized by
Одговорити
(B)
presence of the same number of outermost electrons in the respective atoms
2
The atom of an element X combines with aluminium (\(^{13}\)AI)?
Одговорити
(D)
AI 2X 3
3
The presence of unpaired electrons in an atom of a transition metal gives rise to
Одговорити
(A)
paramagnetism
4
What is responsible for metallic bonding?
Одговорити
(B)
Attraction between the atomic unclei and cloud of electrons
5
Which of the following compounds is covalent?
Одговорити
(D)
CH4
6
A sheet of paper is placed in the path of a beam from a radioactive source. The emissions that pass through the paper consist of
Одговорити
(C)
beta particles and gamma rays
7
Which of the following features of a human skeleton can be determined by carbon-dating?
Одговорити
(C)
Age
8
Which of the following statements about ideal gases is/are correct? 1. The cohesive forces between their particles are negligible ll. They have no definite volume but occupy the volume of their containers III. They are not compressible IV. Their particles collide with loss of energy
Одговорити
(B)
l and ll only
9
P\(_{TOTAL}\) = P\(_1\) + P\(_2\) + P\(_3\) + ...Pn' where P Total is the pressure of a mixture of gasses. The equation above is an expression of
Одговорити
(D)
Dalton's law
10
Which of the following pairs of reagents react to produce hydrogen?
Одговорити
(D)
Magnesium and dilute tetraoxosulphate (VI) acid
11
A mixture of calcium chloride and calcium trioxocarbonate (IV) in water can be separated by
Одговорити
(D)
filtration
12
Which of the following would dissolve in warm dilute H2SO4 without effervescence, to give a blue solution?
Одговорити
(A)
Copper turnings
13
In which of the reactions represented by the following equations is HNO3 behaving as a typical acid?
Одговорити
(A)
CaO + 2HNO3 → Ca(NO3) 2 + H 2O
14
A gas was evolved when a sample of gastric juice reacted with sodium trioxocarbonate (IV) . The gas evolved was
Одговорити
(D)
CO2
15
It can be concluded that gastric juice
Одговорити
(B)
is acidic
16
What does ∆H represent in the following equation ? Cl(g) + e- → CI- (g); ∆H = - 363 kJ mol-1
Одговорити
(B)
Electron affinity
17
Consider the following equation: Ag+ (aq) + CI-(aq) → Ag+CI- (s) ; ∆H = - 65.7 kJmol-1. From the equation, it can be deduced that
Одговорити
(B)
a solid is formed and heat is evolved
18
A reaction is represented by the equation below. A2(g) + B2(g) → 2AB(g); ∆H = +X kJmol-1 Which of the following statements about the system is correct?
Одговорити
(D)
Pressure has no effect on the equilibrium mixture
19
What is the oxidation number of nitrogen in Al(NO\(_3\))\(_3\)?
Одговорити
(C)
+ 5
20
What is oxidized in the reaction represented by the following equation? 3CU + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O
Одговорити
(D)
Copper
21
Which of the following substances decomposes when an electric current is passed through it?
Одговорити
(C)
Hydrochloric acid
22
A concentrated solution containing H+, Cu2+,OH- and CI- was electrolyzed using platinum electrodes which of the ions will be discharged at the cathode?
Одговорити
(B)
Cu2+
23
Given that the order of reactivity of four metals is P>Q>R>S, which of the following reactions is feasible?
Одговорити
(B)
Q + S+ → S + Q+
24
In the electrolysis of CuSO4(aq) using copper electrodes, the reaction at the anode is
Одговорити
(C)
dissolution of copper electrode
25
A feasible cell was constructed by joining the two half cells below. Cu\(^{2+}\) (aq) + 2e\(^-\) → Cu(s) E\(^0\) = +0.34 V; Zn\({^2+}\) + 2e\(^-\) → Zn\((_s)\) E\(^0\) = - 0.76V. What is the standard e.m.f. of the cell?
Одговорити
(D)
+1.1V
26
Hydrogenation of butene yields
Одговорити
(B)
butane
27
Benzene produces more soot than ethene on burning because benzene
Одговорити
(A)
has a higher molar mass
28
One of the products of combustion of pentane in excess air is
Одговорити
(D)
carbon (IV) oxide
29
Which of the following polymers contains nitrogen?
Одговорити
(A)
Nylon
30
What is the function of H2SO4 in the following reaction?
C12H22O11 conc. H2SO4 → 12C + 11H2O
Одговорити
(C)
Dehydrating agent
31
Which of the following constitutes an advantage in the use of hard water?
Одговорити
(D)
Formation of strong bones
32
Sugars can be hydrolyzed at room temperature by the action of
Одговорити
(C)
enzymes
33
If 10 cm 3 of distilled water is added to 10 cm3 of an aqueous salt solution, the concentration of the solution
Одговорити
(B)
decreases
34
Which of the following reactions represents the change that occurs when a photographic film is exposed to sunlight?
Одговорити
(B)
Ag+ + e- → Ag
35
Acidic industrial waste can be treated with
Одговорити
(A)
lime
36
Waste plastics accumulate in the soil and pollute the environment because plastic materials are
Одговорити
(B)
non-biodegradable
37
The conclusion from Rutherford's radioactive substance alpha-scattering experiment is that
Одговорити
(A)
atoms are mostly empty space with a samll
38
If a metal R forms a compound with the formula R(NO3)2 the formula of its tetraoxosulphate (VI) is
Одговорити
(B)
RSO4
39
Which of the following decreases when a given mass of gas is compressed to half its initial volume?
Одговорити
(A)
Average intermolecular distance
40
What volume of hydrogen will be produced if 100cm3 of ammonia is completely decomposed at constant temperature and pressure? The equation for the reaction is 2NH3(g) → N2(g) + 3H2(g)
Одговорити
(B)
150cm3
41
The gas given off when NH4Cl is heated with an alkali is
Одговорити
(D)
NH 3
42
A major factor considered in selecting a suitable method for preparing a simple salt is its
Одговорити
(D)
solubility in water
43
Which of the following acids forms normal salts only?
Одговорити
(D)
Trioxonitrate (V) acid
44
A substance is said to be hygroscopic if it absorbs?
Одговорити
(D)
moisture from the atmosphere without dissolving
45
Which of the following substances increases in mass when heated in air?
Одговорити
(C)
magnesium ribbon
46
Calculate the mass of sodium hydroxide in 5.00 dm3 of a 0.125 mol dm-3 solution [NaOH = 40 g mol]
Одговорити
(D)
25. 0 g
47
Which of the following salt solutions will have a pH greater than 7?
Одговорити
(B)
Na2CO3(aq)
48
What will happen if more heat is applied to the following system at equilibrium? X2(g) + 3Y 2(g) ⇌ 2XY3(g); ∆H =-kJmol -1
Одговорити
(B)
more of XY3 will decompose
49
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?
Одговорити
(B)
Total mass of gas evolved during the reaction
50
CuSO4 5H2O can be obtained from an aqueous solution of copper (ll) tetraoxosulphate (VI) by
