Monday, February 25, 2013

Chemistry MCQS for CSS PMS

Which element has the highest Iomization Energy:
(a) Sodium (b) Aluminium
(c) Calcium (d) Phosphorus

(2) Given the reaction 2CO(g) + O 2 (g)
2CO2(g) when the reaction is subjected to stress, a change will occur in the concentration of:

(a) reactants only
(b)products only
(c) both reactants and products
(d)neither reactants nor products

(3) Which type of reaction is occurring when a metal undergoes corrosion:
(a) Oxidation-reduction (b) Neutralization
(c) Polymerization (d) Saponification
(e) None of these

(4) What is the pH of 0.00001 Molar HCl solution:
(a) 1 (b)9 (c)5
(d) 4 (e) None of these

(5) What is the total number of atoms contained in 2 moles of nickel?
(a) 58.9 (b) 118 (c) 6.02 ´1023
(d) 1.2 ´1024 (e) None of these

(6) What is the percent by mass of oxygen in magnesium oxide (MgO):
(a) 20 % (b) 40 % (c) 50 %
(d) 60 % (e) None of these

(7) Which halogens are gases at STP?
(a) Chlorine and Bromine (b) Chlorine and Fluorine
(c) Iodine and Fluorine (d) Iodine and Bromine

(8) The internal resistance of a liquid to flow is called:
(a) Surface tension (b) Capillary action
(c) Viscosity (d) Van der waals alteraction
(e) None of these

(9) Two Cu Cu2+ couples, A and B are prepared with Cu2+ concentration of exactly
twice that of B. If these two couples are joined to make a cell:
(a) No current will flow (b) Current will flow from A to B
(c) Current will flow from B to A (d) The system will be in equilibrium

(10) The valence of an element:
(a) Always equals the oxidation number
(b) Never equals the oxidation number
(c) Is unrelated to the oxidation number
(d) May be numerically equal to the oxidation number

(11) The basic raw materials used in a Blast furnace to produce Iron are Iron ore, Coke,
Air and:
(a) Scrap Iron (b) Sulphur (c) Sand
(d) Limestone (e) None of these

(12) In contrast to the carbonates of the alkali metals, the alkaline earth carbonates:
(a) Are more soluble
(b) Cannot be isolated
(c) Decompose on heating metal and CO2
(d) Decompose on heating forming oxide and CO2
(e) None of these

(13) Coustic Soda is the common name for:
(a) KOH (b) Na2CO3 (c) K2CO3
(d) NaOH (e) None of these

(14) When 2 g of Copper was heated with Sulphur 2.51 g of sulphide was produced.
The empirical formula of the sulphide is:
(a) Cu S2 (b) Cu2 S
(c) Cu2 S3 (d) None of these

(15) The atomic number of an element is equal to the number of:
(a) Protons in the nucleus (b) Protons and neutrons in the nucleus
(c) Neutrons in the nucleus (d) None of these

(16) A liquid will boil at a given temperature provided the atmospheric pressure is equal
(a) The vapour pressure of the liquid (b) Zero
(c) One atmosphere (d) The critical pressure
(e) None of these

(17) When 12 g of magnesium are dissolved in acid, 1g of hydrogen is produced. What
conclusion may correctly be drawn from this information:
(a) The atomic weight of magnesium is 12
(b) The atomic weight of magnesium is 24
(c) The equivale nt weight of magnesium is 24
(d) Not possible to obtain atomic weight from this information

(18) The more reactive a metal:
(a) The less easily it is oxidized
(b) The more easily it gains electrons
(c) The greater is its tendency to form positive ions
(d) The small is its ionization potential
(e) None of these

(19) Sulphure crystallizes in both monoclinic and rhombic forms. This is an exampleof:
(a) A morphism (b) Isomorphism (c) Allotropy
(d) Supercooling (e) None of these
(20) The oxidation number of sulphur in H2SO4 is:
(a) – 2 (b) +2 (c) + 5
(d) + 4 (e) None of these

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