Ncert Solutions Chemistry Class 12th

The Kjeldahl's method for the estimation of nitrogen can be used to estimate the amount of nitrogen in which one of the following compounds?

The incorrect statement regarding chirality is:

Given below are two statements:

Statement I:
In the coagulation of a negative sol, the flocculating power of the three given ions is in the order- Al³⁺ > Ba²⁺ > Na⁺

Statement II:
In the coagulation of a positive sol, the flocculating power of the three given salts is in the order NaCl > Na₂SO₄ > Na₃PO₄

In the light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements:

Statement I:
Primary aliphatic amines react with HNO₂ to give unstable diazonium salts.

Statement II:
Primary aromatic amines react with HNO₂ to form diazonium salts which are stable even above 300 K.

In the light of the above statements, choose the most appropriate answer from the options given below:

Match List -I with List -II.

List -I
(Drug class)
(a) Antacids
(b) Antihistamines
(c) Analgesics
(d) Antimicrobials

List-II
(Drug molecule)
(i) Salvarsan
(ii) Morphine
(iii) Cimetidine
(iv) Seldane

Choose the correct answer from the options given below:

Given below are two statements:

Statement I:
The boiling points of aldehydes and ketones are higher than hydrocarbons of comparable molecular masses because of weak molecular association in aldehydes and ketones due to dipole-dipole interactions.

Statement II:
The boiling points of aldehydes and ketones are lower than the alcohols of similar molecular masses due to the absence of H-bonding.

In the light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): In a particular point defect, an ionic solid is electrically neutral, even if few of its cations are missing from it unit cells.
Reason (R): In an ionic solid, Frenkel defect arises due to dislocation of cation from its lattice site to interstitial site, maintaining overall electrical neutrality.

In the light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): ICl is more reactive than I?.
Reason (R): I-Cl bond is weaker than I-I bond.

In the light of the above statements, choose the most appropriate answer from the options given below:

When light of wavelength 248 nm falls on a metal of threshold energy 3.0eV, the de-Broglie wavelength of emitted electrons is__________ Angstrom.

AB2 is 10% dissociated in water to A²⁺ and B^-. The boiling point of a 10.0 molal aqueous solution of AB2 is_________ °C. (Round off to the nearest Integer).

[Given : Molal elevation constant of water Kb = 0.5 K kg mol^-1, boiling point of pure water = 100°C]