List of top Chemistry Questions asked in JEE Main

For lead storage battery pick the correct statements:
A. During charging of battery, PbSO4 on anode is converted into PbO2
B. During charging of battery, PbSO4 on cathode is converted into PbO2
C. lead storage battery consists of grid of lead packed with PbO2 as anode
D. lead storage battery - 38% solution of sulphuric acid as an electrolyte
choose the correct answer from the options given below:

Some amount of urea is added to 1000 gm of H2O due to which vapor pressure decreases by 25% of the original vapor pressure. Find out the mass of urea added (Round off to two decimal places)

By weight, 23% NaCl and 19.5% MgCl2 are present in salt water. The degree of dissociation of both salts is 100%. Find the average boiling point of salt water (inºC). (Kb = 0.52 K kg mol–1) (Nearest integer)

A metal chloride contains 55% by mass of chlorine. 100 mL of vapours gives 0.57 gm of chlorine at STP. Calculate the molecular mass of metal chloride. (Nearest integer)

When 2 gm magnesium reasts with excess of HCl and H2 gas is produced then the volume of H2 gas produced is ____ × 10–2 liter at STP. (Nearest Integer)

The number of sp2 hybridized carbon atoms in the following peptide is Ala – Phe – Gly – Ala – Phe - Ley
How many bromo products are formed when ethane is reacted with excess of \(Br_2\) on heating?


Choose the correct option.

 

Match the terms in Column-I with their description in Column-II:

 Column-I Column-II (P) N2O5 (i) N–N bond (Q) N2O (ii) N–O–N bond (R) N2O4 (iii) N=N / NN bond (S) NO2 (iv) N=O bond 

Oxidation number of Mo in Ammonophosphomolybdate

If the radius of ground state hydrogen is 51 pm, find out the radius of 5th orbit of Li2+ ions. (closest integer)

How many moles of \(Ba_3(PO_4)_2\) will be formed by the reaction of \(5\) moles of \(BaCl_2\) and \(3\) moles of \(Na_3(PO_4)\).

The value of log10K for a reaction A ⇋ B is (Given ΔHº298K = –54.67 kJmol–1 ΔSº298K = 10 kJmol–1 and R = 8.314 JK–1mol–1 2.303 × 8.314 × 298 = 5705) 

Determine the amount of urea (NH2CONH2) to be added in 1000 g of water to decrease its vapour presssure by 25%. 
Given: Molar mass of N. C. O and H are 14. 12. 16 and 1 2 mol-1 respectively.

Which of the following slows down the process of setting of the cement ? 

Number of ambidentate ligands in given complex [M(en)(SCN)4] : 

Given below are two statement: one is labelled as Assertion (A) and the other is labelled as Reason (R). 
\(A ⇒\) Spin only magnetic moment of \([Fe(CN)_6]^{–3}\) is \(1.73\) B.M. and \([Fe(H_2O)_6]^{+3}\) is \(5.92\) B.M. 
\(R ⇒\) In both cases Fe have \(+3\) oxidation state. 
In the light of the above statements, write the detailed answer:

Assertion (A) : Radius of H+ is 1.5 × 10–3 pm.
Reason (R) : H+ cannot exist independently.

$SO _2 Cl _2$ on reaction with excess of water results into acidic mixture $SO _2 Cl _2+2 H _2 O \rightarrow H _2 SO _4+2 HCl$ 16 moles of $NaOH$ is required for the complete neutralisation of the resultant acidic mixture The number of moles of $SO _2 Cl _2$ used is :
Choose the correct option. 
major product
Most stable product of the following reaction is:
A compound A on reaction with X and Y produces the same major product but different by product a and b Oxidation of  a gives a substance produced by ants X and Y respectively are :
the same major product but different by product
The geometry around boron in the product 'B' formed from the following reaction is $ BF _3+ NaH \xrightarrow{450 K } A + NaF$ $ A + NMe _3 \rightarrow B$
The IUPAC nomenclature of an element with electronic configuration $[ Rn ] 5 f ^{14} 6 d ^1 7 s ^2$ is :
$20 \,mL$ of $01 \,M \,NH _4 OH$ is mixed with $40\, mL$ of $005\, M \,HCl$ The $pH$ of the mixture is nearest to: (Given: $K _{ b }\left( NH _4 OH \right)=1 \times 10^{-5}, \log 2=030$, $\log 3=048, \log 5=069, \log 7=084$, $\log 11=104$ )