Ncert Solutions Chemistry Class 12th

Portland cement contains 'X' to enhance the setting time. What is 'X'?

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Here 'X' is the Gypsum (CaSO₄.2H₂O) which is used to enhance the setting of time.

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Given below are two statements.

Statement I: Stannane is an example of a molecular hydride.

Statement II: Stannane is a planar molecule.

In the light of the above statement, choose the most appropriate answer from the options given below.

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Stannane is the tetrahedral shape of molecule.

Hybridisation is- sp³, shape and structure are tetrahedral

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Consider the following reactions:

PCl₃ + H₂O -> A + HCl

A + H₂O -> B + HCl

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Number of replaceable H is 2.

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A solution of Fe₂(SO₄)₃ is electrolyzed for 'x' min with a current of 1.5 A to deposit 0.3482g of Fe. The value of x is ______. [nearest integer]

Given : 1F = 96500 C mol^-1

Atomic mass of Fe = 56 g mol^-1

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$F e^{+ 3} + 3 e^{-} \to F e$

3 Faraday is required to deposit 1 mole Fe

$? 56 g$ deposited by $3 * 96500$ C charge

$∴ 0.3482 g$ deposited by $\frac{3 * 96500}{56} * 0.3482 C = \frac{100803.9}{56} C = 1800.7 C$

$∴ Q = I t$

1800.07 = 1.5 t

$∴ t = 1200 s e c = \frac{1200}{60}$ min = 20 min

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In liquation process used for tin (Sn), the metal

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Liquation refining process is applicable for the metal having low m.p, but containing impurities have higher m.p.

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Given below are the critical temperature of some of the gases:

Gas	Critical temperature (K)
He	5.2
CH₄	190.0
CO₂	304.2
NH₃	405.5

The gas showing least adsorption on a definite amount of charcoal is

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Higher adsorbtion of gas is corresponds to higher liquefaction and higher liquefaction is directly proportional to the higher critical temperature.

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An antiseptic dettol is a mixture of two compounds 'A' and 'B' where A has 6π electrons and B has 2π electrons. What is 'B'?

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Dettol is a mixture of

(B) is Terpineol.

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Which of the following ketone will NOT give enamine on treatment with secondary amine?

[Where t-Bu is -C(CH₃)₃]

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Enolisable carbonyl compound gives enamine with 2° amine.

Does not form enol thus not form enamine.

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The major product formed in the following reaction, is

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Kindly consider the following figure

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Which of the following condition or reaction sequence will NOT given acetophenone as the major product?

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