Which of the following salts when dissolved in water will NOT give the corresponding pH value?
отговор
(D)
NaHCO, pH < 6
2
Which of the following is an acidic salt?
отговор
(A)
NaHSO4
3
Which of the following solutions will conduct the least amount of electricity?
отговор
(D)
0.01 M aqueous solution of sugar
4
How many coulombs of electricity are passed through a solution in which 6.5 amperes are allowed to run for 1.0 hour?
отговор
(D)
2.34 x 104 coulombs
5
Which of these represents a redox reaction?
отговор
(D)
Zn + 2HCl → ZnCl2 + H2
6
20 cm3 of 1.0 molar NH4OH solution when neutralized with 20.05cm3 of 0.1 molar HCl liberated -102 joules of heat. Calculate the heat of neutralization of NH4OH?
отговор
(A)
-51.O KJ mol-
7
What is the consequences of increasing pressure on the equilibrium reaction ZnO(s) + H2(g) Zn(s) + H2O(I)?
отговор
(C)
There is no effect
8
The approximate volume of air containing 10cm3 of oxygen is?
отговор
(C)
50 cm3
9
The reaction Mg + H2O → MgO + H2 takes place only in the presence of?
отговор
(D)
steam
10
When steam is passed through red hot carbon, which of the following are produced?
отговор
(C)
Hydrogen and carbon (II) oxide
11
The exhaust fumes from a garage in a place that uses petrol of high sulphur content are bound to contain?
отговор
(B)
CO and SO2
12
Oxygen-demanding waste are considered to be a water pollutant because they?
отговор
(A)
deplete oxygen which is necessary for the survival of aquatic organism
13
Which of the following will react further with oxygen to form higher oxide?
отговор
(C)
SO2 and NO
14
In the course of an experiment, two gases X and Y were produced. X turned wet lead ethanoate to black and Y bleached moist litmus paper. What are the element(s) in each of the gases X and Y respectively?
отговор
(A)
H and S;Cl
15
Which of the following metals does NOT form a stable trioxocarbonate (IV)?
отговор
(E)
none of the options is correct
16
Which of the following sulphides is insoluble in dilute HCl?
отговор
(C)
CuS
17
When chlorine is passed into water and subsequently exposed to sunlight, the gas evolved is?
отговор
(C)
O2
18
A substance Z reacts with NaOH to give salt and water only. When Z is treated with dilute HCl, a gas is evolved which gives a yellow suspension on passing into concentrated H2SO4. Substance Z is?
отговор
(A)
NaHS
19
Ammonia gas is normally dried with?
отговор
(B)
quicklime
20
What are the values of x, y and z respectively in the equation: xCu + yHNO3 → xCu(NO3)2 + 4H2O + zNO?
отговор
(B)
3:8:2
21
The iron (III) oxide impurity in bauxite can be removed by?
отговор
(B)
dissolution in sodium hydroxide and filtration
22
Which of the following does NOT contain aluminium as component?
отговор
(C)
Container for caustic soda
23
A white solid suspected to be lead trioxonitrate (V) zinc trioxocarbonate (IV) or calcium trioxocabonate (IV) was heated strongly. Its residue which was yellow when hot and white when cold is?
отговор
(C)
zinc oxide
24
Which of the following compounds would give lilac flame coloration and a white precipitate with acidified barium chloride solution?
отговор
(C)
K2SO4
25
How will a metal X, which reacts explosively with air and with dilute acids be best extracted from its ores?
отговор
(D)
Electroiysis of fused salt
26
Which of the following is NOT correct test for the named organic compound in each case?
отговор
(B)
Glucose when reacted with Na2CrO4 at 0°C will show immediate discharge of colour
27
Which of the following is used as an 'anti-knock' in automobile engines?
отговор
(B)
Lead tetra-ethyl
28
What reaction takes place when palm-oil is added to potash and foam are observed?
отговор
(B)
Saponification
29
When ethanol is heated with excess concentrated sulphuric acid, the ethanol is?
отговор
(C)
dehydrated to ethene
30
Which of the following compounds is NOT formed by the action of chlorine on methane?
отговор
(B)
C2H5CI
31
Which of the following substance is a mixture?
отговор
(B)
Sea-water
32
The general formula of an alkyl halide (where X represents the halide) is?
отговор
(B)
CnH2n + 1X
33
Which of the following are made by the process of polymerization?
отговор
(B)
Nylon and artificial rubber
34
Starch can be converted to ethyl alcohol by?
отговор
(B)
fermentation
35
The movement of liquid molecules from the surface of the liquid to the gaseous phase above it is known as?
отговор
(C)
evaporation
36
What mass of a divalent metal M (atomic mass = 40) would react with excess hydrochloric acid to liberate 224cm^3 dry hydrogen gas measured at S.T.P?
отговор
(D)
0.4 g
37
In the solubility curve above, water at 98\(^0\)C is saturated with KCl and KCIO\(_3\). What is the percentage of KCl impurity in the crystals formed when the solution is cooled to 30\(^0\)C?
отговор
(D)
26.5
38
In the electrolysis of aqueous solution of K2SO 4 in the above cell, which species migrate to the anode?
отговор
(A)
SO2-OH -
39
The tabulated results below were obtained by titration 10.0 cm3 of water with soup. The titration was repeated with the same sample of water after boiling. The ratio of permanent to temporary hardness is
отговор
(C)
4.1
40
Use the options above to answer this question. Which is the structural formula for pent-2-enoic acid?
отговор
(C)
C
41
10cm3 of hydrogen fluoride gas react with 5cm3 of dinitrogen difluoride gas (N2F2) to form 103 of a single gas. Which of the following is the most likely equation of the reaction?
отговор
(B)
2HF + N2F2 \(\to\) 2NHF2
42
The number of atoms of chlorine present in 5.85g of NaCl is [Avogadro's Number = 6.02 x 10\(^{23}\)]
отговор
(A)
6.02 x 1022
43
How much of magnesium is required to react with 260cm3 of 0.5 M HCl? [Mg = 24]
отговор
(B)
1.5g
44
The relationship between the velocity (U) of gas molecules and their relative molecular mass (M) is shown by the equation
отговор
(C)
U = \(\sqrt{\frac{k}{m}}\)
45
An element with atomic number twelve is likely to be
