The atoms of four elements are represented as 20Q, 16R, 10S and 8T Which of the elements would be unreactive?
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(C)
S
2
Chlorine atom forms \(Cl^{-}\) by
Хариулт
(D)
Gaining one electron
3
An element Z has a combining power of 3. Which of the following formulae is correct of its compounds?
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(C)
Z 2O 3
4
Electrovalent compounds are characterized by
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(C)
high melting point
5
The type of chemical bond that exists between potassium and oxygen in potassium oxide is
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(A)
ionic
6
Which of the following contains co-ordinate covalent bond?
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(C)
NH4
7
Elactrostatic force of attraction between sodium ion and halide ion is greatest in
Хариулт
(C)
NaF
8
Which of the following non-metals reacts most readily with metals?
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(B)
Chlorine
9
A radioactive solid is best stored
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(D)
in a box lined with lead
10
What is the shape of a molecule of CCI4?
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(B)
Tetrahedral
11
What are the values of x and y in the following equation? \(^{234}_{90}\)Th → \(^y_x\)Pa + ß- particle
Хариулт
(A)
91
234
12
Which of the following increases as boiling water changes to steam?
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(B)
degree of disorder in the system
13
9.60 g of a gas X occupies the same volume at 0.30 g of hydrogen under the same conditions. Calculate the molar mass of X [H = 1]
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(D)
64g mol -1
14
Which of the following gases is colourless, odourless and soluble in potassium hydroxide solution?
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(D)
CO2
15
The gas evolved when dilute tetraoxosulphate (VI) acid reacts with sodium hydrogen trioxocarbonate (IV) is
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(C)
carbon (IV) oxide
16
If a solution has a pH of 2, it can be concluded that it
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(D)
will produce effervescence with magnesium ribbon
17
Which of the following salts is stable to heat?
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(A)
K2CO3
18
Which of the following compounds dissolves in water to give an alkaline solution?
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(D)
Potassium oxide
19
Which of the following salts is an acid salt?
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(C)
KHSO4
20
What type of reaction is involved when wood shavings produce a brown gas with concentrated HNO3?
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(A)
Redox reaction
21
Chemical equilibrium is attained when
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(C)
concentrations of the reactants and products remain constant
22
What is the effect of using vanadium (V) oxide as catalyst in the reaction represented by the following equation? 2SO2 + O2 ⇌ 2SO3; ∆H = - xKJmol-1
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(D)
Reduces the time for attainment of equilibrium
23
A finely divided form of a metal burns more readily in air than the rod form because the rod has
Хариулт
(B)
smaller surface area
24
Which of the following will displace copper from a solution of copper (ll) salt?
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(B)
Magnesium
25
What is the value of x in the following equation? Cr2O72- + 14H+ + xe- → 2Cr3+ + 7H2O
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(B)
6
26
In which of the following is the oxidation number of sulphur equal to -2?
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(B)
H2S
27
An iron nail placed in a solution copper (ll) tetraoxosulphate (VI) is soon covered with a deposit of copper. Which of the following equations represents the reactions ?
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(D)
Fe(s) + Cu2+ → Fe2+(aq) + Cu(s)
28
0.10 mol dm-3 NaCI conducts electricity better than 0.10 mol dm-3 CH3COOH because the solution of NaCI
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(A)
contains more ions
29
Which of the following occurs when a solution of CuSO4 is electrolysed using copper electrodes?
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(A)
The cathode becomes coated with copper
30
Which of the following procedures is suitable for identifying the food colouring added to a pastry sample?
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(C)
Do a chromatogram of the colouring extract
31
2 moles of hydrogen gas will react completely with one mole of....
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(D)
CH≡C-CH2-CH3
32
C8H18 will undergo the following reactions except
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(D)
addition
33
Which of the following is correct about both compounds shown below? CH3CH 2CH2OH;CH 3
CH 2CH(OH)CH3
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(C)
Their general molecular formula is the same
34
Which of the following needs to be hydrolyzed before it shows reducing property?
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(C)
Sucrose
35
Two-organic substances are labelled K and L if K gave a blue-black colour with iodine solution and L gave a deep red precipitate with Million's reagent, it can be concluded that
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(A)
K is a carbohydrate and L is a protein
36
A colourless, odourless liquid T, gives effervescence with sodium trioxocarbonate (IV) and a white precipitate with silver trioxonitrate (V) solution T is most probably
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(D)
dilute hydrochloric acid
37
When sodium hydroxide solution is added to a solution of zinc salt, the white precipitate formed re-dissolves in excess sodium hydroxide because
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(C)
zinc hydroxide is amphoteric
38
Which of the following on burning in air contributes to acid rain?
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(A)
Sulphur
39
If 20 cm3 of distilled water is added to 80 cm3 of 0.50 mol dm-3 hydrochloric acid, the concentration of the acid will change to
