The false statement among the followings :

The average residence time of NO is one month
Limestone acts as a sink for SO_x
SO_x can be removed from flue gases by passing through a solution of citrate ions
Ammonia acts as a sink for NO_x

Solution

The average residence time of NO is 4 day.s

Which of the following does not show optical isomerism?

(en = ethylenediamine)

[Co(NH³)³Cl³]⁰
[Co(en)Cl²(NH³)²]⁺
[Co(en)³]³⁺
[Co(en)²Cl²]⁺

Solution

The octahedral coordination compounds of the type MA³B³ exhibit fac-mer isomerism.

Fluorine molecule is formed by

the axial p- p orbital overlap
the sideways p - p orbital overlap
the s - s orbital overlap
the s - p orbital overlap

DIRECTION : These are Assertion-Reason type question.Question contains two statements:Statement-1 (Assertion) and Statement-2 (Reason). Answer these questions from the following four options.

Statement-1 : H₂O₂ is not stored in glass bottles.
Statement-2 :Alkali oxides present in glass catalyse the decomposition of H₂O₂

Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement -1
Statement-1 is True, Statement -2 is True ; Statement-2 is NOT a correct explanation for Statement - 1
Statement-1 is True, Statement- 2 is False
Statement-1 is False, Statement -2 is True

The solubility of PbCl₂ is given by

\(\left [ \frac{K_{sp}}{4} \right ]^{1/3}\)
[8 K_sp]^1/2
[K_sp]^1/2
\(\sqrt{K_{sp}}\)

Solution

Let s be the solubility of PbCl₂ and K_sp be its solubility product

The solubility equilibrium of PbCl₂ is represented as

PbCl₂ ⇌ Pb⁺² + 2Cl^-

∴ K_sp = [Pb⁺²][Cl^-]² = (s)(2s)² = 4s³

⇒ s = \(\left [ \frac{K_{sp}}{4} \right ]^{1/3}\)

Which of the following undergoes nucleophilic substitution exclusively by S_N1 mechanism?

Ethyl chloride
Isopropyl chloride
Chlorobenzene
Benzyl chloride

Solution

Solution

Commercial 10 volume H₂O₂ is a solution with a strength of approximately

Solution

Strength of 10V H₂O₂ = \(\frac{68 \times 10}{22400}\) × 100 = 3.035%

Which one of the following pairs of species have the same bond order?

CN^- and NO⁺
CN^- and CN⁺
\(O_{2}^{-}\) and CN^-
NO⁺ and CN⁺

Solution

Number of moles of NaOH present in 2 litre of 0.5 M NaOH is:

Solution

Given V= 2L, Molarity = 0.5M, Moles =?

Molarity = \(\frac{No.ofmoles of solute}{V ofsolution in L}\) or 0.5 = \(\frac{Moles}{2}\)

∴ Moles = 2 ×0.5 = 1.0

Solution

–OCH₃ activates the benzene ring. –NO₂ deactivates the ring. Hence the reaction of the given compounds with electrophiles is in the order, I >II > III.

Consider the following statements :
1.Atomic hydrogen is obtained by passing hydrogen through an electric arc.
2.Hydrogen gas will not reduce heated aluminium oxide.
3.Finely divided palladium adsorbs large volume of hydrogen gas
4.Pure nascent hydrogen is best obtained by reacting Na with C₂H₅OH Which of the above statements is/are correct ?

1 alone
2 alone
1, 2 and 3
2, 3 and 4

Solution

Pure hydrogen is evolved by reacting absolute alcohol and Na
C₂H₅OH+Na→C₂H₅ONa+½H₂
other statements are correct. See text.

Which of the following has the shortest C – C bond length?

C₂H₅OH
C₂H₆
C₂H₂
C₂H₄

Solution

Because of the triple bond the carbon - carbon bond distance in ethyne is shortest.

Solution

When Cl₂ gas reacts with hot and concentrated sodium hydroxide solution,the oxidation number of chlorine changes from :

zero to +1 and zero to –5
zero to –1 and zero to +5
zero to –1 and zero to +3
zero to +1 and zero to –3

Solution

In which of the following metallic bond is strongest ?

Solution

Strength of metallic bond directly depends on the number of unpaired electrons. More is number of unpaired electrons stronger is metallic bond. Hence,metallic bond is strongest in Cr having maximum of 6 unpaired electrons among the given options, i.e., Sc (1 unpaired electron), V (3 unpaired electrons) and Fe (4 unpaired electrons).

Classical smog occurs in places of

excess SO₂
low temperature
high temperature
excess NH₃

The ionisation potential of a hydrogen atom is –13.6 eV. What will be the energy of the atom corresponding to n = 2.

–3.4 eV
–6.8 eV
–1.7 eV
–2.7 eV

Solution

Energy of an electron E = ^-E₀⁄_n²

For energy level (n = 2)

E = ^-13.6⁄_(2)² = ^-13.6⁄₄ = -3.4 eV.

The pesticide DDT slowly changes to

CCl₃-CHO and chlorobenzene
p, p'-Dichlorodiphenylethene
p, p'-Dichlorodiphenyldichloroethane
p, p'-Dichlorodiphenyldichloroethene

Consider the following transformations :

The molecular formula of C is

ICH₂— COCH₃
CHI₃
CH₃I

Solution

UnAttempted

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