Which of the following can be obtained by fractional distillation?
Trả lời
(A)
Nitrogen from liquid air
2
Which of the following are mixtures?
i, Petroleum
ii, Rubber latex
iii. Vulcanizer's solution
iv, Carbon (II)sulphide
Trả lời
(A)
i, ii and iii
3
An iron ore is known to contain 70.0% Fe2O3. The obtain from 80kg of the ore is?
(Fe = 56, O = 16)
Trả lời
(B)
39.2 kg
4
In two separate experiments, 0.36g and 0.71g of chlorine combined with a metal X to give Y and Z respectively. An analysis showed that Y and Z contain 0.20g and 0.40g of X respectively. The data above represents the law of ?
Trả lời
(C)
constant composition
5
30cm\(^3\) of oxygen at 10 atmospheres pressure is placed in a 20 cm\(^3\) container. Calculate the new pressure if temperature is kept constant?
Trả lời
(B)
15.0 atm
6
Calculate the volume of carbon (IV)oxide measured at s.t.p, produced when 1 kg of potassium hydrogen trioxocarbonate (IV) is totally decomposed by heat?
(G.M.V. at s.t.p 22.4 dm3, K = 39, O = 16, C = 12, H = 1)
Trả lời
(C)
112 dm3
7
A given quantity of a gas occupies a volume of 228 cm3 at a pressure of 750mm Hg. What will be its volume at atmospheric pressure?
Trả lời
(B)
225 cm3
8
A sample of a gas exerts a pressure of 8.2 atm when confined in a 2.93 dm3 container at 20°C. The number of moles of gas in the sample is?
(R = 0.082 litre atm / deg mole)
Trả lời
(A)
1.00
9
Atoms of element X (with 2 electrons in the outer shell). combine with atoms of Y (with 7 electrons in the outer shell). Which of the following statements is FALSE? The compound formed?
Trả lời
(A)
has formula XY
10
The electronic configuration of an elements is 1s22s22p63s23p3. How many unpaired electrons are there in the element?
Trả lời
(C)
3
11
The ions X- and Y+ are isoelectronic, each containing a total of 10 electrons.
How many protons are in the nuclei of the neutral atoms of X and Y respectively?
Trả lời
(D)
9 and 11
12
Which of the following represents the type of bonding present in ammonium chloride molecule?
Trả lời
(C)
Ionic and dative covalent
13
Which of the following is arranged in order of increasing electronegativity?
A quantity of air was passed through a weighed amount of alkaline pyrogallol. An increase in the weight of the pyrogallol would result from the absorption of?
Trả lời
(D)
oxygen
15
Which of the following ions is a pollutant in drinking water even in trace amounts?
Trả lời
(B)
Hg2+
16
The solubility of copper (II) tetraoxosulphate (Iv) is 75g in 100g of water at 100°C and 25g in 100g of water at 30°C. What mass of the salt would crystallize, if 50g of copper (II) tetraoxosulphate (VI) solution saturated at 100°C were cooled to 30°C ?
Trả lời
(D)
14.3
17
A sample of temporary hard water can be prepared in the laboratory by?
Trả lời
(B)
saturating lime water with carbon (IV) oxide
18
A property of a colloidal dispersion which a solution does not have is?
Trả lời
(A)
the Tyndall effect
19
50 cm\(^3\) of sulphur (IV) oxide, 800cm\(^3\) of ammonia, 450 cm\(^3\) of hydrogen chloride, 1.0 cm\(^3\)of Carbon(IV) oxide will respectively saturate 1.0 cm\(^3\) of water at 15°C. Which of the following is suitable for demonstrating the fountain experiment?
Trả lời
(C)
Ammonia and hydrogen chloride
20
How many structural isomers can be written for the alkyl bromide, C4H9Br?
Trả lời
(B)
4
21
What volume of CO2 at s.t.p would be obtained by reacting trioxocarbonate (IV) with excess acid?
(G.M.V at s.t.p = 22.4 dm3)
Trả lời
(B)
22.40 cm 3
22
If a current of 1.5 A is passed for 4.00 hours through a molten tin salt and 13.3g of tin is deposited, what is the oxidation state of the metal in the salt?
(Sn = 118.7, F = 96500 C mol-1)
Trả lời
(B)
2
23
Which of the following equimolar solutions, Na2CO3 Na2 SO 4CI FeCI3 CH3COONa,
have pH greater than 7?
Trả lời
(C)
Na2CO3 and CH3COONa
24
MnO-4 + 8H+ + ne → Mn++ + 4H2O. Which is the value of n in the reaction above?
a redox reaction in which SO2 is the oxidant and H2S is the reductant
26
Magnesium (IV) oxide is known to hasten the decomposition of hydrogen peroxide. Its main action is to?
Trả lời
(C)
lower the activation energy for the reaction
27
1.1 g of CaCI2 dissolved in 50 cm3 of water caused a rise in temperature of 3.4°C. The heat of reaction, ∆H for CaCI2 in kj per mole is?
(Ca = 40, CI = 35.5, specific heat of water is 4.18 jk-1)
Trả lời
(A)
-71.1
28
NO(g) + CO(g) ↔ (1)/(2)N2(g) + CO2(g) ∆H = 89.3 kj.
What conditions would favour maximum conversion of nitrogen (II) oxide and carbon (II) oxide in the reaction above?
Trả lời
(A)
Low temperature and high pressure
29
Which of the following equilibria is unaffected by a pressure change?
Trả lời
(B)
H 2(g) + I2(g) ↔ 2HI(g)
30
Which of the following gases will rekindle a brightly glowing splint?
Trả lời
(C)
N2O
31
Which of the following salts can be melted without decomposition?
Trả lời
(A)
Na2CO3
32
Oxygen gas can be prepared by heating?
Trả lời
(C)
potassium trioxonitrate (V)
33
Addition of aqueous ammonia to a solution of Zn++ gives a white precipitate which dissolves in an excess of ammonia because?
Trả lời
(C)
zinc forms a complex which is readily soluble in excess ammonia
34
Which of the following, in clear solution, forms a white precipitate when carbon (IV) oxide is bubbled into it for a short time?
Trả lời
(C)
Ca(OH)2
35
Which of the following metals can be prepared in samples by the thermal decomposition of their trioxonitrate (V) salts?
Trả lời
(C)
Mercury and silver
36
Copper (II) tetraoxosulphate (IV) is widely used as a?
Trả lời
(B)
fungicide
37
Which of the following compounds can exist as geometric isomers?
Trả lời
(B)
But-2-ene
38
How many grams of bromine will be required to completely react with 10 g of propyne?
(C = 12, H = 1, Br = 80)
Trả lời
(D)
80 g
39
Ethene when passed into concentrated H2SO4 is rapidly absorbed. The product is diluted with water and then warmed to produce?
Trả lời
(A)
ethanol
40
One advantages of detergents over soap is that detergents?
Trả lời
(C)
form soluble salts with hard water
41
A certain liquid has a high boiling point. It is viscous, non-toxic, miscible with water being very hygroscopic. This liquid is most likely to be?
Trả lời
(D)
CH2OHCHOHCH2OH
42
Is known as?
Trả lời
(B)
1-chloro-2-methylpropane
43
Which of the following statements is TRUE of the complete hydrolysis of a glycerine by sodium hygroxide?
Trả lời
(A)
3 moles ofNaOH are required for each mole of glyceride
44
Which of the following are the products of the reaction between CH3COOH and CI2 in sunlight?
