CHEMISTRY - MOCK - 01
1. Number of atoms in the following samples of substances is the largest in :
(1) 127.0g of iodine
(2) 48.0g of magnesium
(3) 71.0g of chlorine
(4) 4.0g of hydrogen
2. The ratio of mass percent of C and H of an organic compound (CxHyOz) is 6 : 1. If one molecule of the above compound ( CxHyOZ ) contains half as much oxygen as required to burn one molecule of compound CXHY completely to CO2 and H2O. The empirical formula of compound CxHyOz is :
(1) C2H4O
(2) C3H4O2
(3) C2H4O3
(4) C3H6O3
3. The concentrated sulphuric acid that is peddled commercially is 95% H2SO4 by weight. If the density of this commercial acid is 1.834 g cm-3, the molarity of this solution is :-
(1) 17.8 M
(2) 15.7 M
(3) 10.5 M
(4) 12.0 M
4. The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1 : 4. The ratio of number of their molecule is :
(1) 1 : 8
(2) 3 : 16
(3) 1 : 4
(4) 7 : 32
5. 3g of activated charcoal was added to 50 mL of acetic acid solution (0.06N) in a flask. After an hour it was filtered and the strength of the filtrate was found to be 0.042 N. The amount of acetic acid adsorbed (per gram of charcoal) is :
(1) 42 mg
(2) 54 mg
(3) 18 mg
(4) 36 mg
6. The density of a solution prepared by dissolving 120 g of urea (mol. mass = 60 u) in 1000 g of water is 1.15 g/mL. The molarity of this solution is
(1) 2.05 M
(2) 0.50 M
(3) 1.78 M
(4) 1.02 M
7. The ratio of number of oxygen atoms (O) in 16.0g oxygen (O), 28.0 g carbon monoxide (CO) and 32.0g oxygen (O2) is :
(Atomic mass :C =12, O =16 and Avogadro’s constant NA = 6.0 * 1023 mol-1)
(1) 3 : 1 : 1
(2) 1 : 1 : 2
(3) 3 : 1 : 2
(4) 1 : 1 : 1
8. When CO2 (g) is passed over red hot coke it partially gets reduced to CO(g). Upon passing 0.5 litre of CO2 (g) over red hot coke, the total volume of the gases increased to 700 mL. The composition of the gaseous mixture at STP is :
(1) CO2 = 200 mL: CO = 500mL
(2) CO2 = 350 mL: CO = 350mL
(3) CO2 = 0.0 mL: CO = 700mL
(4) CO2 = 300 mL: CO = 400mL
9. An open vessel at 300 K is heated till ⅖ th of the air in it is expelled. Assuming that the volume of the vessel remains constant, the temperature to which the vessel is heated is :
(1) 750 K
(2) 400 K
(3) 500 K
(4) 1500K
10. The density of 3M solution of sodium chloride is 1.252 g mL-1. The molality of the solution will be (molar mass, NaCl = 58.5 g mol-1)
(1) 2.18 m
(2) 3.00 m
(3) 2.60 m
(4) 2.79 m