Practice Online test 1 - general science mcq Online Quiz (set-1) For All Competitive Exams
Q-1) In the following equations : NaCO3 + xHCL ⟶ 2NaCl + CO2 + H2O, the value x is
(a)
(b)
(c)
(d)
Na2CO3 2HCl ⟶ 2NaCl CO2 + H2O
Q-2) The total number of atoms represented by the compound CuSO4 .5H2O is
(a)
(b)
(c)
(d)
1 atom of Cu + 1 atom of sulphur + 9 atoms of oxygen + 10 atoms of hydrogen.
Total number of atoms in the compound is 21.
Q-3) Which one is a bivalent ion?
(a)
(b)
(c)
(d)
Ca++ and S– –
Q-4) Slow eating away of iron articles in the presence of moist air is called
(a)
(b)
(c)
(d)
Rusting is a process in which iron gets converted into hydrated iron oxide in presence of moisture.
$2Fe + 3/2O_2 + xH_2O ⟶ {Fe_2O_3.xH_2O} ↙ {rust}$
Q-5) An organic compound containing C, H and O gave on analysis C – 40% and H – 6.66%. Its empirical formula would be
(a)
(b)
(c)
(d)
| Element | % | At.Wt. | Rel.Number | Ratio | ||||
| C | 40 | 12 | $40/12$= 3.33 | ${3.33}/{3.33}=1$ | ||||
| H | 6.66 | 1 | ${6.66}/1$= 6.66 | ${6.66}/{3.33}=2$ | ||||
| O | 53.34 | 16 | ${53.34}/16$= 3.33 | ${3.33}/{3.33}=1$ |
Q-6) In the reaction : PbO + C ⟶ Pb + CO
(a)
(b)
(c)
(d)
In this carbon reduces PbO to Pb so carbon (C) is reducing agent (reductant) PbO acts as oxidising agent (oxidant) as it oxidises C to CO.
Q-7) $Na_2S_2O_3$ represent the compound
(a)
(b)
(c)
(d)
Q-8) The branch of chemistry which deals with study of the methods of detection and determination of elements and compounds is
(a)
(b)
(c)
(d)
Q-9) Valency of an atom or radicals is
(a)
(b)
(c)
(d)
Q-10) When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is formed. This is an example of
(a)
(b)
(c)
(d)
${CuSO_4} ↙{(Blue)} + H_2S ⟶ {CuS ↓} ↙(Black) + H_2SO_4$