Which of the following electrons configurations correctly represents an inert element?
Trả lời
(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
Trả lời
(B)
Nuclar fusion
4
Which of the following ions has the electron configuration 2,8,8?
Trả lời
(D)
CI-
5
An element with the electron configuration of 1s 22s 22p 6 would have a combining power of
Trả lời
(A)
o
6
Rare gases are stable because they
Trả lời
(D)
have octet structure
7
Which of the following elements would produce coloured ions in aqueous solution?
Trả lời
(B)
lron
8
The energy change that accompanies the addition of an electron to an isolated gaseous atom is
Trả lời
(C)
electron affinity
9
Which of the following hydrohalic acids is the weakest?
Trả lời
(D)
HI
10
Which of the following arrangements is in order of increasing metallic property?
Trả lời
(A)
Li < Na< k
11
Chlorine, bromine and iodine belong to the same group and
Trả lời
(D)
react with alkali
12
Which of the following elements can conveniently be placed in two groups in the periodic table ?
Trả lời
(C)
Hydrogen
13
The bond formed when two electrons that are shared between two atoms are donated by only one of the atoms is
Trả lời
(B)
dative
14
When element 20A combines with element 8Y,
Trả lời
(B)
an ionic compound AY is formed
15
In metallic colids, the forces of attraction are between the mobile valence electrons and
Trả lời
(D)
positively charged nuclei
16
Which of the following statements about displacement reaction is correct?
Trả lời
(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]
Trả lời
(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
Trả lời
(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]
Trả lời
(B)
2.0 moles
20
The number of atoms in one mole of a substance is equal to the
Trả lời
(D)
avogadro number
21
Which of the following statements about a molar solution is correct? it
Trả lời
(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
Trả lời
(C)
lighter than air
23
Bubbling excess carbon (IV) oxide into calcium hydroxide solution results in the formaton of
Trả lời
(B)
Ca(HCO3)2
24
The equation P = \(\frac{K}{V}\) illustrates
Trả lời
(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
Trả lời
(D)
341 K
26
Which of the following equimolar solutions has the highest conductivity?
Trả lời
(C)
H 2SO 4(aq)
27
The colour of phenolphthalein indicator in alkaline solution at the end-point of an acid-base titration is?
Trả lời
(C)
pink
28
Which of the following statements about enthalpy of neutralization is correct? It
Trả lời
(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
Trả lời
(A)
the process is endothermic
30
Which of the following metallic oxides is amphoteric?
Trả lời
(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?
Trả lời
(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
Trả lời
(B)
forward reaction would favoured
33
What is the value of n in the following equation? Cr2O72- + 14H+ + ne- → 2Cr 3+ + 7H2O
Trả lời
(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]
Trả lời
(B)
11.8 g
35
Which of the following metals could be used as sacrifical anode for preventing the corrosion of iron?
Trả lời
(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?
Trả lời
(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?
Trả lời
(D)
2,2,4 - trimethylpentane
38
Which of the following compounds would react with ethanoic acid to give a sweet smelling liquid?
Trả lời
(B)
Alkanol
39
Which of the following separation techniques would show that black ink is a mixture of chemical compounds?
Trả lời
(B)
Chromatography
40
The following substances are examples of addition polymer except
Trả lời
(A)
nylon
41
When bromine is added to ethene at room temperature, the compound formed is
Trả lời
(D)
1,2 - dibromoethane
42
The compound that makes palm wine taste sour after exposure to the air for few days is
Trả lời
(A)
ethanol
43
The reagent that can be used to distinguish ethene from ethyne is
Trả lời
(A)
ammoniacal silver trioxonitrate (V) solution
44
The following substances are ores of metals except
Trả lời
(D)
graphite
45
Which of the following processes does not involve the use of limestone?
Trả lời
(B)
Manufacture of tetraoxosulphate (VI) acid by Contact process
