Which of the following electrons configurations correctly represents an inert element?
отговор
(D)
1s22s22p6
3
What type of reaction is represented by the following equation?\(\frac{2}{1}\)D\(\frac{3}{1}\)H → \(\frac{4}{4}\)He + \(\frac{1}{0}\)n + energy
отговор
(B)
Nuclar fusion
4
Which of the following ions has the electron configuration 2,8,8?
отговор
(D)
CI-
5
An element with the electron configuration of 1s 22s 22p 6 would have a combining power of
отговор
(A)
o
6
Rare gases are stable because they
отговор
(D)
have octet structure
7
Which of the following elements would produce coloured ions in aqueous solution?
отговор
(B)
lron
8
The energy change that accompanies the addition of an electron to an isolated gaseous atom is
отговор
(C)
electron affinity
9
Which of the following hydrohalic acids is the weakest?
отговор
(D)
HI
10
Which of the following arrangements is in order of increasing metallic property?
отговор
(A)
Li < Na< k
11
Chlorine, bromine and iodine belong to the same group and
отговор
(D)
react with alkali
12
Which of the following elements can conveniently be placed in two groups in the periodic table ?
отговор
(C)
Hydrogen
13
The bond formed when two electrons that are shared between two atoms are donated by only one of the atoms is
отговор
(B)
dative
14
When element 20A combines with element 8Y,
отговор
(B)
an ionic compound AY is formed
15
In metallic colids, the forces of attraction are between the mobile valence electrons and
отговор
(D)
positively charged nuclei
16
Which of the following statements about displacement reaction is correct?
отговор
(A)
A more electropositive element displaces a less electroposive one
17
The volume occupied by 17g of H2S at s.t.p. is [H = 1.00, S = 32.0, Molar volume = 22.4 dm3]
отговор
(A)
11.2dm 3
18
Consider the reaction represented by the following equation: xKMnO 4(aq) + ySO2(g) + zH2O(I) → K 2SO4(AQ) + 2MnSO4(aq) + 2H2SO x,y and z are respectively
отговор
(A)
2,5 and 2
19
What is the amount of magnesium that would contain 1.20 x 1024 particles? [Mg = 24, Avogadro's constant = 6.02 x 1023]
отговор
(B)
2.0 moles
20
The number of atoms in one mole of a substance is equal to the
отговор
(D)
avogadro number
21
Which of the following statements about a molar solution is correct? it
отговор
(D)
contains one mole of the solute in 1 dm3 of solution
22
A gas that is collected by upward delivery is likely to be
отговор
(C)
lighter than air
23
Bubbling excess carbon (IV) oxide into calcium hydroxide solution results in the formaton of
отговор
(B)
Ca(HCO3)2
24
The equation P = \(\frac{K}{V}\) illustrates
отговор
(A)
Boyle's law
25
The initial volume of a gas at 300 K was 220 cm 3 Determine its temperature if the volume became 250 cm 3
отговор
(D)
341 K
26
Which of the following equimolar solutions has the highest conductivity?
отговор
(C)
H 2SO 4(aq)
27
The colour of phenolphthalein indicator in alkaline solution at the end-point of an acid-base titration is?
отговор
(C)
pink
28
Which of the following statements about enthalpy of neutralization is correct? It
отговор
(A)
is constant for a strong acid and a strong base
29
When NH 4CI was dissolved in water, the container was cold to touch. This implies that
отговор
(A)
the process is endothermic
30
Which of the following metallic oxides is amphoteric?
отговор
(A)
AI2O3
31
On evaporation to dryness, 250 cm3 of saturated solution of salt X with relative molar mass 101 gave 50.5g of the. What is the soluility of the salt?
отговор
(B)
2.0 mol dm-3
32
Consider the following reaction equation:
X(g) + Y(g) ⇌ XY(g); ∆H = + 220KJ mol-1 If the temperature of the system is increased, the
отговор
(B)
forward reaction would favoured
33
What is the value of n in the following equation? Cr2O72- + 14H+ + ne- → 2Cr 3+ + 7H2O
отговор
(C)
6
34
What mass of copper would be formed when a current of 10.0 A is passed through a solution of CuSO4 for 1 hour? [Cu = 63.5; 1F = 96500C]
отговор
(B)
11.8 g
35
Which of the following metals could be used as sacrifical anode for preventing the corrosion of iron?
отговор
(C)
Magnesium
36
Consider the following electrochemical cell notation: M(s) / M2+ (aq)// H+ (aq)/ H2(g). The value of the electrode potential is positive when?
отговор
(B)
electrons fow from hydrogen electrode, H2(g) to metal electrode, M(s)
37
Which of the following compounds determines the octane rating of petrol?
отговор
(D)
2,2,4 - trimethylpentane
38
Which of the following compounds would react with ethanoic acid to give a sweet smelling liquid?
отговор
(B)
Alkanol
39
Which of the following separation techniques would show that black ink is a mixture of chemical compounds?
отговор
(B)
Chromatography
40
The following substances are examples of addition polymer except
отговор
(A)
nylon
41
When bromine is added to ethene at room temperature, the compound formed is
отговор
(D)
1,2 - dibromoethane
42
The compound that makes palm wine taste sour after exposure to the air for few days is
отговор
(A)
ethanol
43
The reagent that can be used to distinguish ethene from ethyne is
отговор
(A)
ammoniacal silver trioxonitrate (V) solution
44
The following substances are ores of metals except
отговор
(D)
graphite
45
Which of the following processes does not involve the use of limestone?
отговор
(B)
Manufacture of tetraoxosulphate (VI) acid by Contact process
