Question

1) The branch of Chemistry which deals with carbon compounds is called ------------- *
1 अंक
A) Organic
B) Inorganic
C) Carbon
D) Bio
2) The percentage of oxygen in NaOH is ---------- *
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A) 40 %
B) 60 %
C) 8 %
D) 10 %
3) The separation of binary mixture of acetone and methyl alcohol is done by ---------- *
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A) Simple distillation
B) Fractional distillation
C) Fractional crystallization
D) Re-crystallization
4) Which of the following statements about the electron is INCORRECT? *
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A) It is a negatively charged particle.
B) The mass of electron is equal to the mass of neutron.
C) It is a basic constituent of all atoms.
D) It is a constituent of cathode rays.
5) ---------- elements are known as chalcogens. *
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A) Group 17
B) Group 18
C) Group 16
D) Group 1
6) The diagonal relationship between Li and Mg is due to the similarity in --------- *
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A) Ionic sizes
B) Electronegativity value
C) Polarizing power
D) All of the above
7) ---------- has noble gas core plus 14 f-electrons and 10 d-electrons. *
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A) Gallium
B) Indium
C) Thallium
D) Boron
8) A/an --------------- is a simple combination of two or more substances in which the constituent substances retain their separate identities. *
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A) Compound
B) Mixture
C) Element
D) Molecule
9) ---------- reagent is the reactant that reacts completely but limits further progress of the reaction. *
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A) Oxidizing
B) Reducing
C) Limiting
D) Excess
10) Which of the following solvents is most commonly used for the crystallization of copper sulphate? *
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A) Water
B) Acetone
C) Ether
D) Methanol
11) The energy difference between the shells goes on ---------- when moved away from the nucleus. *
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A) Increasing
B) Decreasing
C) Equalizing
D) Static
12) Which element has the most negative electron gain enthalpy? *
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A) Sulphur
B) Fluorine
C) Chlorine
D) Hydrogen
13) The alkali metal that reacts with nitrogen directly to form nitride is ---------- *
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A) Li
B) Na
C) K
D) Rb
14) ---------- is the most electronegative element of group 14. *
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A) Carbon
B) Silicon
C) Germanium
D) Tin
15) Which of the following has the largest number of atoms? *
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A) 1 g Au (s)
B) 1 g Na (s)
C) 1 g Li (s)
D) 1 g Cl2 (g)
16) How many grams of water will be produced by complete combustion of 12 g of methane gas? *
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A) 16
B) 27
C) 36
D) 56
17) In distillation of liquid, water condenser is used ---------- *
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A) to boil the liquid
B) to collect the liquid
C) to condense hot vapours of the liquid
D) to adsorb the liquid
18) Principal quantum number describes ---------- *
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A) shape of the orbital
B) size of the orbital
C) spin of electron
D) orientation of the orbital electron cloud
19) Which of the properties remain unchanged on descending a group in the periodic table? *
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A) Atomic size
B) Density
C) Valency electrons
D) Metallic character
20) The first ionization enthalpies of alkaline earth metals are ---------- than those of the corresponding alkali metals. *
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A) Higher
B) Lower
C) Same
D) Zero
21) Which of the following is NOT a mettaloid? *
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A) B
B) Sn
C) Ge
D) Sb
22) The maximum number of electrons in a subshell for which l=3 is ---------- *
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A) 14
B) 10
C) 8
D) 4
23) Which of the following forms a bridge between reactive s-block elements and less reactive group 13 and 14 elements? *
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A) Inert gases
B) Transition metals
C) Halogens
D) Inner transition metals
24) Which of the following is the radioactive alkali metal? *
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A) Rubidium
B) Caesium
C) Francium
D) Beryllium
25) ---------- cannot expand its octet due to absence of d orbital in its valence shell. *
1 अंक
A) Ga
B) C
C) As
D) Ge​

Answer 1

Explanation:

1). Organic chemistry is most simply defined as the study of the compounds of carbon. Inorganic chemistry is the study of chemical elements and their compounds (with the exception of carbon compounds).

2). 40.000%

3). Fractional distillation is employed for a separating mixture of two or more volatile liquids having boiling points close to each other. Acetone has a boiling point 60∘ C, whereas methanol has a boiling point of 65∘ C. Hence, it can be separated by fractional distillation.

4). ___

5). ___

16). 27 grams

Answer 2

Answer:

The nucleus contains all the positive charge of the atom and also__________ of its mass.

(a) 90.9% (b) 99.9% (c) 80.9% (d) 79.9%