List of top Chemistry Questions asked in JEE Main

Match List-I with List-II
 List I List II
A.Lyophilic colloidiLiquid-liquid colloid
B.EmulsioniiProtective colloid
C.Positively chargediii\(FeCl_3 + NaOH\)
D.Negatively chargediv\(FeCl_3 + hot\; water\)

Choose the correct answer from the options given below :

Match List I with List II
List I EnzymeList II Conversion of
AInvertaseIStarch into maltose
BZymaseIIMaltose into glucose
CDiastaseIIIGlucose into ethanol
DMaltaseIVCane sugar into glucose

Choose the most appropriate answer from the options given below:

Match List-I with List-II
 (Polymer)  (Used in)
A.BakeliteiRadio and television cabinets
B.GlyptaliiElectrical switches
C.PVCiiiPaints and Lacqures
D.PolystyreneivWater pipes

Choose the correct answer from the options given below:

Which of the following will have maximum stabilization due to crystal field?
The number of radial and angular nodes in 4d orbital are, respectively
Match List-I with List-II.
 List I List II
A.Concentration ofiAniline
B. Leaching of aluminaiiNaOH
C.Froth stabilizeriii\(SO_2\)
D.Blister copperivNaCN

Choose the correct answer from the options given below.

Which of the following elements is considered as a metalloid?
The role of depressants in ‘Froth Floation method’ is to
Match List-I with List-II
List-I
(A) Spontaneous process
(B) Process with \(ΔP = 0\), \(ΔT = 0\)
(C) \(ΔH_{reaction}\)
(D) Exothermic Process
List-II
(I) \(ΔH < 0\)
(II) \(ΔG_{T,P} < 0\)
(III) Isothermal and isobaric process
(IV) [Bond energies of molecules in reactants] – [Bond energies of product molecules]
Choose the correct answer from the options given below :
Based upon VSEPR theory, match the shape (geometry) of the molecules in List-I with the molecules in
List-II and select the most appropriate option.
  List-I                            List-II
(Shape)                    (Molecules)
(A) T-shaped             (I) XeF4
(B) Trigonal planar     (II) SF4
(C) Square planar       (III) CIF3
(D) See-saw                (IV) BF3
Match List-I with List-II.
 (Si-Compounds) (Si-Polymeric/other
Products)
A.\((CH_3)_4Si\)iChain Silicone
B.\((CH_3)Si(OH)_3\)iiDimeric Silicone
C.\((CH_3)_2Si(OH)_2\)iiiSilane
D.\((CH_3)_3Si(OH)\)iv2D-Silicone

Choose the correct answer from the options given below:

Given below are two statements one is labelled as Assertion A and the other is labelled as Reason R:

Assertion A: The amphoteric nature of water is explained by using Lewis acid/base concept

Reason R: Water acts as an acid with NH3 and as a base with H2S.

In the light of the above statements choose the correct answer from the options given below:

Which one of the following compounds is used as a chemical in certain type of fire extinguishers?

Solute A associates in water. When 0.7 g of solute A is dissolved in 42.0 gof water, it depresses the freezing point by 0.2°C. The percentage association of solute A in water is :

[Given : Molar mass of A = 93 g mol–1. Molal depression constant of water is 1.86 K kg mol–1.]

Using very little soap while washing clothes, does not serve the purpose of cleaning of clothes, because:

Choose the correct answer :

1. The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is

[Given The threshold frequency of platinum is 1.3 × 1015 s–1 and h = 6.6 × 10–34 Js.]

\(PCl_5\) is well known, but \(NCl_5\) is not. Because,

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Polluted water may have a value of BOD of the order of 17 ppm.

Reason R: BOD is a measure of oxygen required to oxidise both the bio-degradable and non-biodegradable organic material in water.

In the light of the above statements, choose the most appropriate answer from the options given below.

Metals generally melt at very high temperature. Amongst the following, the metal with the highest melting point will be
The correct order of bond orders of \(C_2^{2-}, N_2^{2-}, O_2^{2-}\) is, respectively
Which one of the following is an example of artificial sweetner?
The Ksp for bismuth sulphide (Bi2S3) is 1.08 × 10–73. The solubility of Bi2S3 in mol L–1 at 298 K is
In the industrial production of which of the following, molecular hydrogen is obtained as a byproduct?
The energy of one mole of photons of radiation of wavelength \(300\) \(nm\) is (Given \(h\) = \(6.63 × 10^{–34}\)Js, \(N_A\) = \(6.02 × 10^{23}\) \(mol^{–1}\), \(c = 3 × 10^8\) \(ms^{–1}\))
\(120 \;g\) of an organic compound that contains only carbon and hydrogen gives \(330\) \(g\) of \(CO_2\) and \(270\) \(g\) of water on complete combustion. The percentage of carbon and hydrogen, respectively are