WB JEE 2020

Ph\(-\)
CDO\(\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{Warm}^{50\% aq.NaOH}}\)
Ph\(-\)
COO\(\mathop H\limits^\Theta\)
+ an alcohol.This alcohol is

The product in the above reaction is

The reduction product of ethyl 3-oxobutanoate by NaBH4 in methanol is

What is the major product of the following reaction?

The maximum number of electrons in an atom in which the last electron filled has the quantum numbers n = 3, l = 2 and m = \(-\)
1 is

The radius of the first Bohr orbit of a hydrogen atom is 0.53 \(\times {10^-8}\) cm. The velocity of the electron in the first Bohr orbit is

The difference between orbital angular momentum of an electron in a 4f -orbital and another electron in a 4s-orbital is

The number of unpaired electrons in the uranium (92U) atom is

For the above three esters, the order of rates of alkaline hydrolysis is

A homonuclear diatomic gas molecule shows 2-electron magnetic moment. The one-electron and two-electron reduced species obtained from above gas molecule can act as both oxidising and reducing agents. When the gas molecule is one-electron ox...

Bond order of He2, \(He_2^ +\) and \(He_2^{2 + }\) are respectively

The equilibrium constant for the following reactions are given at 25\(^\circ\)C\(2A\) \(\rightleftharpoons\) B + C, K1 = 1.0\(2B\) \(\rightleftharpoons\) C + D, K2 = 16\(2C + 2D\) \(\rightleftharpoons\) 2P, K3 = 25The equilibrium constant ...

For a reaction 2A + B \(\to\) P, when concentration of B alone is doubled, t1/2 does not change and when concentrations of both A and B is doubled, rate increases by a factor of 4. The unit of rate constant is,

Indicate the correct IUPAC name of the coordination compound shown in the figure.

The reaction for obtaining the metal (M) from its oxide (M2O3) ore is given by\({M_2}{O_3}(s) + 2Al(l)\buildrel {Heat} \over \longrightarrow A{l_2}{O_3}(l) + 2M(s)\), (s = solid, l = liquid) in that case, M is

At 273 K temperature and 76 cm Hg pressure the density of a gas is 1.964 g L-1. The gas is

For the following carbocations, the correct order of stability is I. \(^ \oplus C{H_2} - COC{H_3}\)II. \(^ \oplus C{H_2} - OC{H_3}\)III. \(^ \oplus C{H_2} - C{H_3}\)

The correct order of acidity for the following compounds is :

\(C{H_3} - O - C{H_2} - Cl\mathrel{\mathop{\kern0pt\longrightarrow} \limits_\Delta ^{aq{.^\Theta }OH}} C{H_3} - O - C{H_2} - OH\)Which information below regarding this reaction is applicable?

\(Me - C \equiv C - Me\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{EtOH, - 33^\circ C}^{Na/N{H_3}(liq.)}} \underline{\underline X} \,\buildrel {dil.alkaline\,KMn{O_4}} \over \longrightarrow \,\text{Product(s)}\)The product(s) from th...

Which of the following reactions give(s) a meso-compound as the main product?

The total number of alkyl bromides (including stereoisomers) formed in the reaction \(M{e_3}C - CH = C{H_2} + HBr \to\) will be

How and why does the density of liquid water change on prolonged electrolysis?

A solution is saturated with SrCO3 and SrF2. The \([CO_3^{2 - }]\) is found to be 1.2 \(\times\) 10-3 M. The concentration of F- in the solution would be Given : Ksp(SrCO3) = 7.0 \(\times\) 10-10,Ksp(SrF2) = 7.9 \(\times\) 10-10

Which of the following compounds is asymmetric?

Equal masses of ethane and hydrogen are mixed in an empty container at 298 K. The fraction of total pressure exerted by hydrogen is

Kf (water) = 1.86 K kg mol-1. The temperature at which ice begins to separate from a mixture of 10 mass % ethylene glycol is

Which of the following statements is not true for the reaction, 2F2 + 2H2O \(\to\) 4HF + O2 ?

To a solution of a colourless efflorescent sodium salt, when dilute acid is added, a colourless gas is evolved along with formation of a white precipitate. Acidified dichromate solution turns green, when the colourless gas is passed through...

In the face centered cubic lattice structure of gold the closest distance between gold atoms is ('a' being the edge length of the cubic unit cell)

5 mL of 0.1 M Pb(NO3)2 is mixed with 10 mL of 0.02 M KI. The amount of PbI2 precipitated will be about

The mole fraction of ethanol in water is 0.08. Its molality is

Which of the following has the largest number of atoms?

What will be the mass of one atom of 12C?

Which of the following statement(s) is/are incorrect?

SiO2 is attacked by which one/ones of the following?

In the extraction of Ca by electro reduction of molten CaCl2 some CaF2 is added to the electrolyte for the following reason :

Among the following, the ion which will be more effective for flocculation of Fe(OH)3 solution is :

An ideal gas expands adiabatically against vacuum. Which of the following is correct for the given process?

For spontaneous polymerisation, which of the following is (are) correct?