List of top Chemistry Questions asked in JEE Main

To find the standard potential of \(\mathrm{M^{3+}/M}\) electrode, the following cell is constituted :
\(\mathrm{Pt/M/M^{3+}(0.001\ mol\ L^{-1})/Ag^{+}(0.01\ mol\ L^{-1})/Ag}\)
The emf of the cell is found to be 0.421 volt at 298 K. The standard potential of half reaction \(\mathrm{M^{3+} + 3e^{-} \to M}\) at 298 K will be :
(Given \(E^{\ominus}_{\mathrm{Ag^{+}/Ag}}\) at 298 K = 0.80 Volt)

Adsorption of a gas on a surface follows Freundlich adsorption isotherm. Plot of \(\log\frac{x}{m}\) versus \(\log p\) gives a straight line with slope equal to 0.5, then :
(\(\frac{x}{m}\) is the mass of the gas adsorbed per gram of adsorbent)

50 mL of 0.2 M ammonia solution is treated with 25 mL of 0.2 M HCl. If \(\mathrm{p}K_\mathrm{b}\) of ammonia solution is 4.75, the pH of the mixture will be :

The IUPAC name of the following compound is :

The major product of the following reaction is :
\(\mathrm{C_6H_5CH_2-\underset{Br}{\overset{CH_3}{C}}-CH_2-CH_3}\) \(\xrightarrow[\mathrm{C_2H_5OH}]{\mathrm{C_2H_5ONa}}\)

The major product of the following reaction is :

1. K₂CO₃
2. CH₃I (1 eq.)

Which of the following compounds will not undergo Friedel Craft’s reaction with benzene ?

A mixture containing the following four compounds is extracted with 1M HCl. The compound that goes to aqueous layer is :

The major product expected from the following reaction is :

The major product of the following reaction is :
\(\mathrm{CH_3\underset{Br}{CH}CH_2\underset{Br}{CH}CH_2CH_3} \xrightarrow[\text{heat}]{\mathrm{KOH,\ CH_3OH}}\)

The reason for “drug induced poisoning” is :

Which of the following statements is not true about partition chromatography ?

In which of the following reactions, hydrogen peroxide acts as an oxidizing agent ?

A metal ‘M’ reacts with nitrogen gas to afford ‘M₃N’. ‘M₃N’ on heating at high temperature gives back ‘M’ and on reaction with water produces a gas ‘B’. Gas ‘B’ reacts with aqueous solution of \(\mathrm{CuSO_4}\) to form a deep blue compound. ‘M’ and ‘B’ respectively are :

A solution containing a group-IV cation gives a precipitate on passing \(\mathrm{H_2S}\). A solution of this precipitate in dil.HCl produces a white precipitate with NaOH solution and bluish-white precipitate with basic potassium ferrocyanide. The cation is :

Consider the following ionization enthalpies of two elements ‘A’ and ‘B’.

Element	Ionization enthalpy (kJ/mol)
	1st	2nd	3rd
A	899	1757	14847
B	737	1450	7731

Which of the following statements is correct ?

Consider the following standard electrode potentials (E° in volts) in aqueous solution :

Element	M3+ / M	M+ / M
Al	−1.66	+0.55
Tl	+1.26	−0.34

Based on these data, which of the following statements is correct ?

Identify the pollutant gases largely responsible for the discoloured and lustreless nature of marble of the Taj Mahal.

The enthalpy change on freezing of 1 mol of water at 5\(^\circ\)C to ice at \(-5^\circ\)C is :
(Given \(\Delta_{fus}H = 6\) kJ mol^-1 at 0\(^\circ\)C, \(C_p(\mathrm{H_2O}, l) = 75.3\) J mol^-1 K^-1, \(C_p(\mathrm{H_2O}, s) = 36.8\) J mol^-1 K^-1)

The rate of a reaction A doubles on increasing the temperature from 300 to 310 K. By how much, the temperature of reaction B should be increased from 300 K so that rate doubles if activation energy of the reaction B is twice to that of reaction A.

5 g of \(\mathrm{Na_2SO_4}\) was dissolved in x g of \(\mathrm{H_2O}\). The change in freezing point was found to be 3.82\(^\circ\)C. If \(\mathrm{Na_2SO_4}\) is 81.5% ionised, the value of x (\(K_f\) for water = 1.86\(^\circ\)C kg mol^-1) is approximately :
(molar mass of S = 32 g mol^-1 and that of Na = 23 g mol^-1)

The pair of compounds having metals in their highest oxidation state is :

Which of the following is paramagnetic ?

Among the following, the incorrect statement is :

The formation of which of the following polymers involves hydrolysis reaction?