Chemistry:2018:CBSE:[All India]: Set-II
To Access the full content, Please Purchase
Write the IUPAC name of the following:
The IUPAC name of the following compound is 3,3-dimethylpentan–2–ol.
Out of chlorobenzene and benzyl chloride, which one gets easily hydrolysed by aqueous NaOH and why?Marks:1
Benzylchloride readily undergoes hydrolysis with aqueous NaOH as compared to chlorobenzene due to following reasons.
(i)In Chlorobenzene, the electron pair on chlorine atom is in conjugation with pi- electrons of the ring. Therefore, C-Cl bond acquires partial double bond character due to resonance and it does not undergo hydrolysis easily.
(ii) In Chlorobenzene, Cl is attached to sp2 hybridised carbon atom whereas in benzylchloride it is attached to sp3 hybridised carbon atom.Therefore,bond length in chlorobenzene is shorter. Since, it is difficult to break a shorter bond than a longer bond; therefore, chlorobenzene does not undergo hydrolysis easily.
CO(g) and H2(g) react to give different products in the presence of different catalysts. Which ability of the catalyst is shown by these reactions?Marks:1
The selectivity of a catalyst is its ability to direct a reaction to yield a particular product. This property of enzymes enables CO and H2 to give different products when they react in the presence of different catalysts.
Write the coordination number and oxidation state of Platinum in the complex [Pt(en)2Cl2].Marks:1
en is a bidentate ligand and chlorine is a monodentate ligand.
Hence, the coordination number of Platinum is 6.
Let x be the oxidation state of Platinum in the complex
So, x + 0+ (–1 x 2) = 0
x = +2
Therefore, the oxidation state of Platinum is +2in the complex [Pt(en)2Cl2].
Analysis shows that FeO has a non-stoichiometric composition with formula Fe0.95O. Give reason.Marks:1
Iron existsin nature in +2 and +3 oxidation states. Therefore, the composition of iron oxide is non-stoichiometric.
How do you convert the following?
(a) Ethanal to Propanone
(b) Toluene to Benzoic acidMarks:2
(a) Ethanal to propanone
(b) Toluene to Benzoic acid
Account for the following:
(a) Aromatic carboxylic acids do not undergo Friedel-Crafts reaction.
(b) pKa value of 4-Nitrobenzoic acid is lower than that of benzoic acid.Marks:2
a. Carboxylic acids do not undergo Friedel-Crafts reaction because the catalyst aluminium chloride (Lewis acid) gets bonded to the carboxyl group.
b. 4–Nitrobenzoic acid has nitro group at the para position which is an electron withdrawing group. In general, the electron withdrawing groups increase the acidity of carboxylic acids by stabilising the conjugate base through delocalisation of the negative charge by inductive and/or resonance effects.
For the reaction
2N2O5(g) → 4NO2(g) + O2(g),
the rate of formation of NO2(g) is 2.8 x 10-3Ms-1. Calculate the rate of disappearance of N2O5(g).Marks:2
Among the hydrides of Group-15 elements,which have the
(a) lowest boiling point?
(b) maximum basic character?
(c) highest bond angle?
(d) maximum reducing character?Marks:2
a) lowest boiling point: PH3
b) maximum basic character : NH3
c) highest bond angle : NH3
d) maximum reducing character: BiH3