Class 12 Chemistry - Chapter Surface Chemistry NCERT Solutions | Explain what is observed (i) When a b

Why is adsorption always exothermic?

What do you mean by activity and selectivity of catalysts?

Explain the following terms:

(i) Electrophoresis

(ii) Coagulation

(iii) Dialysis

(iv) Tyndall effect.

What modification can you suggest in the Hardy-Schulze law?

What is an adsorption isotherm? Describe Freundlich adsorption isotherm.

Explain the terms with suitable examples:

(i) Alcosol

(ii) Aerosol

(iii) Hydrosol

How are colloids classified on the basis of

(i) Physical states of components

(ii) Nature of dispersion medium and

(iii) Interaction between dispersed phase and dispersion medium?

Discuss the effect of pressure and temperature on the adsorption of gases on solids.

Why does physisorption decrease with the increase of temperature

What are the factors which influence the adsorption of a gas on a solid?

For the reaction R → P, the concentration of a reactant changes from 0.03 M to 0.02 M in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and seconds.

Write the formulas for the following coordination compounds:

(i) Tetraamminediaquacobalt (III) chloride

(ii) Potassium tetracyanonickelate(II)

(iii) Tris(ethane-1,2-diamine) chromium(III) chloride

(iv) Amminebromidochloridonitrito-N-platinate(II)

(v) Dichloridobis(ethane-1,2-diamine)platinum(IV) nitrate

(vi) Iron(III) hexacyanoferrate(II)

(i) Write structures of different isomeric amines corresponding to the molecular formula, C4H11N

(ii) Write IUPAC names of all the isomers.

(iii) What type of isomerism is exhibited by different pairs of amines?

Why are solids rigid?

Write the structures of the following compounds.

(i) α-Methoxypropionaldehyde

(ii) 3-Hydroxybutanal

(iii) 2-Hydroxycyclopentane carbaldehyde

(iv) 4-Oxopentanal

(v) Di-sec-butyl ketone

(vi) 4-Fluoroacetophenone

Which of the ores mentioned in Table 6.1 can be concentrated by magnetic separation method?

Why are pentahalides more covalent than trihalides?

Silver atom has completely filled d orbitals (4d10) in its ground state. How can you say that it is a transition element?

Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.

Write structures of the following compounds:

(i) 2-Chloro-3-methylpentane

(ii) 1-Chloro-4-ethylcyclohexane

(iii) 4-tert. Butyl-3-iodoheptane

(iv) 1,4-Dibromobut-2-ene

(v) 1-Bromo-4-sec. butyl-2-methylbenzene

A 5% solution (by mass) of cane sugar in water has freezing point of 271 K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 K.

What are the different types of RNA found in the cell?

Explain how does the -OH group attached to a carbon of benzene ring activate it towards electrophilic substitution?

Why are cimetidine and ranitidine better antacids than sodium hydrogencarbonate or magnesium or aluminium hydroxide ?

The decomposition of NH₃on platinum surface is zero order reaction. What are the rates of production of N₂and H₂if k = 2.5 x 10^-4mol^-1L s^-1?

Write the names of monomers of the following polymers:

Is it true that under certain conditions, Mg can reduce SiO₂ and Si can reduce MgO? What are those conditions?

Can you store copper sulphate solutions in a zinc pot?

Amongst the following ions which one has the highest magnetic moment value?

(i) [Cr(H₂O)₆]³⁺

(ii) [Fe(H₂O)₆]²⁺

(iii) [Zn(H₂O)₆]²⁺

What is meant by unidentate, didentate and ambidentate ligands? Give two examples for each.