Class 12th

If the wavelength for an electron emitted from H-atom is 3.3 * 10^-10m, then energy adsorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is ___________times. (Nearest integer)

[Given: h = 6.626 * 10^-34 Js]

Mass of electron = 9.1 * 10^-31 kg

Metal M crystallizes into a fcc lattice with the edge length of 4.0 * 10^-8cm. The atomic mass of the metal is_________ g/mol. (Nearest integer)

(Use: N_A = 6.02 * 10²³mol^-1, density of metal, M = 9.03 g cm^-3).

2L of 0.2 M H₂SO₄ is reacted with 2L of 0.1 M NaOH solution, the molarity of the resulting product Na₂SO₄ in the solution is_________ millimolar (Nearest integer)

At $20.0\mathrm{m}\mathrm{L}$ solution containing $0.2\mathrm{g}$ impure ${\mathrm{H}}_2{\mathrm{O}}_2$ reacts completely with $0.316\mathrm{g}$ of ${\mathrm{K}\mathrm{M}\mathrm{n}\mathrm{O}}_4$ in acid solution. The purity of ${\mathrm{H}}_2{\mathrm{O}}_2$ (in %) is (mol. wt. of ${\mathrm{H}}_2{\mathrm{O}}_2=34$ ; mol. wt. of ${\mathrm{K}\mathrm{M}\mathrm{n}\mathrm{O}}_4=158$ ) 

The number of chiral centres present in $\left[\mathrm{B}\right]$ is

The mass of ammonia in grams produced when $2.8\mathrm{k}\mathrm{g}$ of dinitrogen quantitatively reacts with $1\mathrm{k}\mathrm{g}$ of dihydrogen is(Mole Concept)

Given below are two statements : One is labeled as Assertion A and the other is labeled as Reason R

Assertion A: Thin layer chromatography is an adsorption chromatography.

Reason R: A thin layer of silica gel is spread over a glass plate of suitable size in thin layer chromatography which acts as an adsorbent.

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

If $75\mathrm{\%}$ of a first order reaction was completed in 90 minutes, $60\mathrm{\%}$ of the same reaction would be completed in approximately (in minutes)

(Take: $\mathrm{l}\mathrm{o}\mathrm{g}2=0.30;\mathrm{l}\mathrm{o}\mathrm{g}2.5=0.40$ )(Kinetics)

Two statement in respect of drug- enzyme, interaction are given below.

Statement I: Actin of an enzyme can be blocked only when an inhibitor blocks the active site of the enzyme.

Statement II: An inhibitor can form a strong covalent bond with the enzyme.

In the light of the above statements, choose the correct answer from the options given belowf