List of top Chemistry Questions

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: $K _{ b }\left( NH _4 OH \right)=1 \times 10^{-5}, \log 2=030$, $\log 3=048, \log 5=069, \log 7=084$, $\log 11=104$ )
The depression in freezing point observed for a formic acid solution of concentration $05\, mL\, L ^{-1}$ is $00405^{\circ} C$ Density of formic acid is $105 \, g \, mL ^{-1}$ The Van't Hoff factor of the formic acid solution is nearly : (Given for water $k _{ f }=186 \, K \, kg \, mol ^{-1}$ )