The reaction between sulphur (IV) oxide and oxygen is represented by the equilibrium reaction 2SO2(g) + O2(g) ↔ 2SO3(g), ∆H = -196 kJ. What factor would influence increased production of SO3(g)?
پاسخ دهید
(C)
Decrease in the temperature of the reaction
2
Magnesium ribbon was allowed to burn inside a given gas P leaving a white solid residue Q. Addition of water to Q liberated a gas which produced dense white fumes with a drop of hydrochloric acid. The gas P was?
پاسخ دهید
(A)
nitrogen
3
The best treatment for a student who accidentally poured concentrated tetraoxosulphate (VI) acid on his skin in the laboratory is to wash the skin with?
پاسخ دهید
(A)
cold water
4
In which of the following pairs of element is allotropy exhibited by each element?
پاسخ دهید
(D)
Oxygen and sulphur
5
Which of the following gases can best be used for demonstrating the fountain experiment?
i) Nitrogen (ii) Ammonia (iii) Nitrogen (I) oxide
(iv) Hydrogen chloride.
پاسخ دهید
(C)
ii and iv
6
When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by?
پاسخ دهید
(C)
passing it directly through calcium oxide
7
Which of the following elements will form oxide which will dissolve both in dilute HNO3 and NaOH solutions to form salts?
پاسخ دهید
(A)
Al
8
Stainless steel is an alloy of?
پاسخ دهید
(C)
iron, carbon and chromium
9
Alloys are best prepared by?
پاسخ دهید
(D)
cooling a molten mixture of the necessary elements
10
Corrosion is exhibited by?
پاسخ دهید
(D)
all metals
11
Inspite of the electronic configuration, 1s22s22p2, carbon is tetraavalent because?
پاسخ دهید
(C)
both the 2s and 2p orbitals hybridizes
12
Which of the following compounds will give a precipitate with an aqueous ammoniacal solution of copper (l) chloride?
پاسخ دهید
(B)
CH3 ≡ CCH3
13
The efficiency of petrol as a fuel in high-compression internal combustion engines improves with an increase in the amount of?
پاسخ دهید
(A)
branched chain alkanes
14
Ethanol reacts with aqueous sodium mono-oxoio date (l) to give a bright yellow solid with a characteristic smell. The product is?
پاسخ دهید
(B)
triodomethane
15
The most volatile fraction obtained from fractional distillation of crude petroleum contains?
پاسخ دهید
(D)
methane, ethane and propane
16
Local black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the?
پاسخ دهید
(C)
alkali
17
Synthetic rubber is made by polymerization of?
پاسخ دهید
(A)
2 methyl buta - 1, 3 - diene
18
Complete oxidation of propan -1- ol gives?
پاسخ دهید
(D)
propanoic acid
19
When water drops are added to calcium carbide in a container and the gas is passed through a jet and lifted, the resultant flame is called an?
پاسخ دهید
(C)
oxyacetylene flame
20
The greater the different in electronegativity between bonded atoms, the?
پاسخ دهید
(B)
higher the polarity of the bond
21
A stream of air was successively passed through three tubes X, Y and Z containing a concentrated aqueous solution of KOH, red hot copper powder and fused calcium chloride respectively. What was the composition of the gas emanating from tube Z?
پاسخ دهید
(D)
water vapour, N2 and the inert gases
22
In the purification of town water supply, alum is used principally to?
پاسخ دهید
(D)
coagulate small pasrticles of mud
23
Which of the following water samples will have the highest titre value when titrated for the Ca2+ ions using soap solution?
پاسخ دهید
(A)
Permanently hard water after boiling
24
Oil spillage in ponds and creeks can be cleaned up by?
پاسخ دهید
(B)
spraying with detergent
25
The solubility of Na3AsO4(H2O)12 is 38.9g per 100g H2O. What is the mass percentage of Na3AsO4 in the saturated solution?
(As = 75, Na = 23, O = 16, H = 1)
پاسخ دهید
(D)
13.7%
26
In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity?
پاسخ دهید
(C)
Hydrochloride acid, ethanol acid, sodium chloride, milk of magnesia and sodium hydroxide
27
If 24.83 cm3 of 0.15 M NaOH is titrated to its end point with 39.45 cm3
of HCl, what is the molarity of the HCl?
پاسخ دهید
(A)
0.094 M
28
The atomic numbers of two elements X and Y are 12 and 19 respectively. The bond of these two elements is?
پاسخ دهید
(C)
Metallic
29
If d represents the density of a gas and K is a constant, the rate of gaseous diffusion r is related to d by the equation?
پاسخ دهید
(A)
r = k/√d
30
An isotope has an atomic number of 17 and a mass number of 36. Which of the following gives the correct number of neutrons and protons in an atom of the isotope?
