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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

1.

What is the name given to a pure substance with only one kind of atoms?

Answer»

ELEMENT
compound
mixture
SUSPENSION

SOLUTION :element
Discussion
2.

What is the difference between pure gold and 22 carat gold? Which type of gold is used for making ornaments ?

Answer»

Solution : Pure gold is a 24 carat gold, which is very soft, hence ornaments cannot be made from it, while 22 carat gold is an ALLOY (mixture) of 22 parts of pure gold and 2 parts of either copper or silver and it is HARD. As a result, 22 carat gold is used for MAKING designed ornaments.
Discussion
3.

The term pH was coined by ______

Answer»

SOLUTION :SORENSEN
Discussion
4.

Write the formula of the product formed when the element A (atomic number 19) combines with the element B (atomic number 17). Draw its electronic dot structure. What is the nature of the bond formed?

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SOLUTION :
Discussion
5.

Which of the following metal is not found in a free state ?

Answer»

AG
AU
PT
Al

Answer :D
Discussion
6.

Why are alcohols poor conductors of electricity ?

Answer»

SOLUTION :Because they do not PRODUCE IONS in solution.
Discussion
7.

Which one of the following element is used as the standard for measuring the relativeatomic mass of an element in now a days?

Answer»

`""_(1)H^(2)`
`""_(6)O^(12)`
`C-12`
`C-14`

Solution :`C-12`
Discussion
8.

The thickness of _______ increases in the electrorefming of copper

Answer»


ANSWER :CATHODE
Discussion
9.

What do you think would happen when a mixture of iron filings and sulphur powder is heated ?

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Solution :Ferrours SULPHIDE, a COMPOUND of IRON and sulphur, will be FORMED.
Discussion
10.

What is the formula of the next homologue of propene (C_3H_6)?

Answer»

Solution : Since the HOMOLOGUES differ by `-CH_2` unit in their formulae, the next HOMOLOGUE of propene is `C_3H_6 + CH2toC_4H_8` . It is the molecular formula of BUTENE.
Discussion
11.

Which two of the following compounds could belong to the same homologous series ? C_(2)H_(6)O_(2),C_(2)H_(6),CH_(4)O

Answer»

Solution :`C_(2)H_(6)O` and `CH_(4)O` having difference in molecular formula EQUAL to - `CH_(2)` belong to the same homologous series of alcohols `(C_(3)H_(5)OHandCH_(3)OH)`.
Discussion
12.

Which of the following is (are) the correct isomer(s) of pentane ?

Answer»

`CH_(3) - CH = underset(CH_(3))underset(|)C-CH_(3)`
`CH_(3)-CH_(2)- underset(CH_(3))underset(|)C = CH_(2)`
`CH_(3) -underset(CH_(3))underset(|)CH=CH-CH_(3)`
`CH_(3)= overset(CH_(3))overset(|)underset(CH_(3)underset(|)= CH- CH_(3) `

Answer :D
Discussion
13.

Which of the following affect solubility?

Answer»

TEMPERATURE
NATURE of SOLUTE and SOLVENT
Pressure
all the above

SOLUTION :all the above
Discussion
14.

Which has more number of atoms ? 1.0 g Na or 1.0 g Mg

Answer»


ANSWER : 1.0 G NA
Discussion
15.

Write word equations and then balanced equations for the reaction taking place when dilute hydrochloric acid reacts with magnesium ribbon

Answer»

Solution :Dilute hydrochloric ACID REACTS with magnesium RIBBON FORMING magnesium chloride and evolving hydrogen gas
Magnesium + Hydrochloric acid `rarr` Magnesium chloride + hydrogen
`Mag(s) + 2HCl (aq) rarr MgCl_(2)(aq) + H_(2)(g)`
Discussion
16.

Write word equations and then balanced equations for the reaction taking place when dilute hydrochloric acid reacts with iron filings

Answer»

Solution :Dilute hydrochloric acid REACTS with iron filings to GIVE iron CHLORIDE and hydrogen gas. Iron + Hydrochloric acid `rarr` Iron chloride + Hydrogen
`Fe(s) + 2HCL (aq) rarr FeCl_(2)(aq) +H_(2)(g)`
Discussion
17.

Write the property of electrical conductivity of carbon compounds.

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SOLUTION :CARBON COMPOUNDS are non-conductor of ELECTRICITY.
Discussion
18.

Which of the following is a redox reaction ?

Answer»

`CaCO_(3) to CAO + CO_(2)`
`H_(2) + CI_(2)to 2HCI`
`CaO + 2HCI to CaCI_(2) + H_(2)O`
`NaOH + HCI to NaCI + H_(2)O`

Answer :D
Discussion
19.

What will be the structural formula and electron dot structure of cyclopentane?

Answer»

Solution :The molecular formula of cyclopentane is `C_(5)H_(10)`. Five CARBON ATOMS of cyclopentane are connected by SINGLE bonds in a cyclic FORM. Following are the structural formula and elecgtron dot STRUCTURE of cyclopentane.
Discussion
20.

Translate the statement into chemical equations and then balance them: Hydrogen gas combine with nitrogen to form ammonia.

Answer»

SOLUTION :`underset("NITROGEN")(N_(2)(g)) +underset("HYDROGEN")(3H_(2)(g)) to underset("Ammonia")(2NH_(3)(g))`
Discussion
21.

Which one will not migrate towards cathode in an electrolytic cell ?

Answer»

Lead ion
Chloride ion
Potassium ion
Calcium ion

Answer :B
Discussion
22.

Write the formula and name of the lower homologue of ethanoic acid.

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SOLUTION :HCOOH = Methanoic ACID
Discussion
23.

When marble chips are treated with HCI , which of the following gas is liberated?

Answer»

`CO_2`
`O_2`
`CO`
`NO_2`

ANSWER :A
Discussion
24.

Which of the following equations is (are) not correctly balanced ?

Answer»

`Mg+2HCI to MgCI_(2)+H_(2)`
`2KNO_(3) to 2KNO_(2) +O_(2)`
`N_(2)+2H_(2) to 2NH_(3)`
`2KCIO_(3) to 2KCI + 3O_(2)`

Answer :C
Discussion
25.

Translate thestatements into chemical equations and then balance them: Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.

Answer»

SOLUTION :`underset("Barium CHLORIDE")(BaCl_(2)(aq))+ underset("Almunium sulphate")(Al_(2)(SO_(4))_(3)) to underset("Aluminium chloride")(2AlCl_(3)(aq))+ underset("Barium sulphate")(3BaSO_(4))`
Discussion
26.

What is that instrument which can detect the presence of electric current in a circuit.

Answer»

Galvanometer
Motor
Generator
None of above

Answer :1
Discussion
27.

Which of the following is an allotrope of carbon ?

Answer»

Diamond
Graphite
Buckminster Fullerene
All the above

Solution :All the THREE are ALLOTROPES of CARBON.
Discussion
28.

Write the balanced equation for the chemical reactions : Hydrogen + Chlorine Hydrogen chloride

Answer»

Solution :`H_(2)(G)+ Cl_(2)(g) to 2HCL(g)`
Discussion
29.

What is the chemical formula of baking soda?

Answer»

SOLUTION :CHEMICAL formula of BAKING SODA is `NaHCO_3` .
Preparation
`NAOH + CO_2 to NaHCO_2`
Discussion
30.

There are three elements E, F, G with atomicnumbers 19, 8 and 17 respectively. Classify the elements as metals and nonmetals.

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Solution : E = METAL, F = nonmetal, G = nonmetal
Discussion
31.

Zinc reacts with sodium hydroxide to form……….

Answer»

Zinc HYDROXIDE +`H_(2)O`
SODIUM zincate+`H_(2)`
Zinc OXIDE +`H_(2)`
Zinc oxide +`H_(2)O`

Answer :A::B::C::D
Discussion
32.

What change does zinc undergo when it is reactedwith dilute H_(2)SO_(4) ?

Answer»

SOLUTION :A zinc atom LOSES two electrons and GETS oxidized into ` ZN^(2+)` ion.
` Zn to Zn^(2+) +2e`
Discussion
33.

Which metals produce fire on water ?

Answer»

Solution :Sodium and POTASSIUM PRODUCE FIRE on WATER.
Discussion
34.

Which one of the following has the largest ionisation energy?ArClKAl

Answer»

AR
Cl
K
Al

Solution :Ar
Discussion
35.

Which one of the following elements exhibit maximum number of valence electrons ?

Answer»

Na
Al
Si
P

ANSWER :D
Discussion
36.

What is the maximum number of electrons present in the main energy level in which the 'g' subshell appears for the first time? Find the atomic number of the element to be discovered in which the differentiating electron is the only electron in the first 'g' subshell

Answer»

Solution :Corresponding 'f' value of 'g' subshell is '4'. Principal quantt1m number in which 'g' subshell can exist is '5'. The maximum number of electron!r that can be accommodated in fifth orbit is 2 x 52 = 50 electrons. Orbitals to be filled before filling of 'Sg' subshell are: 1s, 2s, 2p, 3s, 3P, 4s, 3d, 4p, 5s, 4D, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6D, 7p, 8s, 5g. Atomic number of the ELEMENT should be 121.
Discussion
37.

Which of the following metals exist in free state in nature ? Cu , Al , Mg , Au , Fe , Ag

Answer»

SOLUTION :AU and AG
Discussion
38.

The structural formula of ethyne is______.

Answer»

SOLUTION :`H - C -= C - H`
Discussion
39.

water gets decomposed when heated above100^(@)C

Answer»


ANSWER :F
Discussion
40.

Three elements A, B and C have 3, 4 and 2 electrons respectively in their outermost shell. Give the group number to which they belong in the Modern Periodic Table. Also, give their valencies.

Answer»

SOLUTION :
Discussion
41.

Three elements having a single electron in theiroutermost shell.

Answer»

Solution :(i) LITHIUM (LI) (2,1) (ii) SODIUM (Na) (2, 8 1)(iii) Potassium (K) (2 , 8,8 ,1).
Discussion
42.

Transition elements : cl-block :: Inner transitionelements : ___________

Answer»

Solution :f-block - The d-block elements have 2 incompleteoutermost SHELLS whereas the f-block elementshave 3 OUTERMOST shells which are INCOMPLETE .
Discussion
43.

The state in which molecular attractions are very strong is

Answer»

solid
liquid
gas
none of these

Solution :PROTONS, NEUTRONS and ELECTRONS all three are subatomic particles. Neutrons and Protons are present inside the nucleus while electron revolves AROUND the nucleus.
Discussion
44.

WhenSO_(2) gas is allowed to react with acidified potassiumdichromate solution , the yellow colour of the solution changes to green. This is due to the formation of

Answer»

`Cr_(2)O_(3)`
`Cr_(2)(SO_(4))_(3)`
`K_(2)SO_(4)`
`H_(2)SO_(3)`

Answer :B
Discussion
45.

Which one of the following is an example of a heterogeneous mixture ?

Answer»

ALUM and water
Lime and water
Sodium CHLORIDE and water
Sand and SUGAR

ANSWER :D
Discussion
46.

What is Electronegativity?

Answer»

SOLUTION : ELECTRONEGATIVITY of an ELEMENT is the measure of the tendency of its atom to ATTRACT the shared pair of electrons towards itself in a covalent bond.
Discussion
47.

What is the maximum number of electrons present in the main energy level in which thegsubshell appears for the first time? Find the atomic number of the element to be discovered in which the dif- ferentiating electron is the only electron in the first 'g'subshell.

Answer»

Solution :(i)LVALUE for 'g' subshell
(ii) total number of degenerate orbitals in'g'subshell
(III) number of ELECTRONS in'g'subshell
(iv) main energy level in Which'g' subshell first APPEARS
(v) orbitals that have lower energy than the flrstg orbital
Discussion
48.

Which one is an oxide of group 2 metal?

Answer»

MGO
`K_2O`
`Na_2O`
`Al_2O_3

Solution :MgO
Discussion
49.

What is formed on burning magnesium ?

Answer»

SOLUTION : Magnesium oxide (MGO) is formed on BURNING magnesium.
Discussion
50.

Write the essential condition for following reaction to take place : 2AgBr to 2Ag+Br_(2) Write one application of this reaction.

Answer»

Solution :`2AgBroverset("Sunlight")(to)2Ag+Br`
PRESENCE of sunlight is NECESSARY for the reaction to take place.
This reaction is USED in black and white PHOTOGRAPHY.
Discussion