Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

Explain the following:

Carbon and hydrogen are not used as reducing agents at high temperatures.

PH₃ forms bubbles when passed slowly in water but NH₃ dissolves. Explain why?

SF₆ is known but SCl₆ is not. Why?

On reaction with \[\ce{Cl2}\], phosphorus forms two types of halides ‘A’ and ‘B’. Halide A is yellowish-white powder but halide ‘B’ is colourless oily liquid. Identify A and B and write the formulas of their hydrolysis products.

White phosphorus reacts with chlorine and the product hydrolyses in the presence of water. Calculate the mass of \[\ce{HCl}\] obtained by the hydrolysis of the product formed by the reaction of 62 g of white phosphorus with chlorine in the presence of water.

Due to the presence of ambidentate ligands coordination compounds show isomerism. Palladium complexes of the type \[\ce{Pd(C6H5)2 (SCN)2]}\] and \[\ce{[Pd(C6H5)2 (NCS)2]}\] are ______.

The compounds \[\ce{[CO(SO4)(NH3)5]Br}\] and \[\ce{[Co(SO4)(NH3)5]Cl}\] represent

What kind of isomerism exists between \[\ce{[Cr(H2O)6]Cl3}\] (violet) and \[\ce{[Cr(H2O)5Cl]Cl2 . H2O}\] (greyish-green)?

Which of the following complexes show linkage isomerism?

(i) \[\ce{[Co(NH3)5 (NO2)]^{2+}}\]

(ii) \[\ce{Co(H2O)5 CO]^{3+}}\]

(iii) \[\ce{[Cr(NH3)5 SCN]^{2+}}\]

(iv) \[\ce{Fe(en)2 Cl2]^+}\]

Name the type of isomerism when ambidentate ligands are attached to central metal ion. Give two examples of ambidentate ligands.

Match the complex species given in Column I with the possible isomerism given in Column II and assign the correct code:

Assertion: Linkage isomerism arises in coordination compounds containing ambidentate ligand.

Reason: Ambidentate ligand has two different donor atoms

CoSO₄Cl.5NH₃ exists in two isomeric forms ‘A’ and ‘B’. Isomer ‘A’ reacts with AgNO₃ to give white precipitate, but does not react with BaCl₂. Isomer ‘B’ gives white precipitate with BaCl₂ but does not react with AgNO₃. Answer the following questions.

1. Identify ‘A’ and ‘B’ and write their structural formulas.
2. Name the type of isomerism involved.
3. Give the IUPAC name of ‘A’ and ‘B’.

The process of converting alkyl halides into alcohols involves ______.

Mark the correct increasing order of reactivity of the following compounds with HBr/HCl.

(a)
(b)
(c)

Name the factors responsible for the solubility of alcohols in water.

Suggest a reagent for the following conversion.

Alcohols react with active metals e.g. Na, K etc. to give corresponding alkoxides. Write down the decreasing order of reactivity of sodium metal towards primary, secondary and tertiary alcohols.

Explain why is OH group in phenols more strongly held as compared to OH group in alcohols.

Explain why nucleophilic substitution reactions are not very common in phenols.