11.

Which one of the following statements is not correct?

• The hydration enthalpies of alkali metal ions decrease down the group.

• LIthium halides are some what covalent in nature

• Alkali metals react with water liberating oxygen gas

• KO₂ is paramagnetic.

Identify the statement which is not correct?

• Dehydrobrominaton of 2-bromopentane gives pent-1-ene as the major product

• Freon 12 is manufactured by Swarts reaction

• CHCl₃ is stored in closed, dark coloured bottles

• Chronic exposure to CHCl₃ causes liver damage

The gaseous products formed at cathode (X) and anode (Y), when an aqueous solution of sodium acetate is electrolysed are

• X	Y
  CO2	C2H6, H2

• X	Y
  H2, CO2	C2H6

• X	Y
  H2	C2H6, CO2

• X	Y
  C2H6, H2	CO2

Identify the correct statements from the following
(i) Electromeric effect is a permanent effect

(ii) Hyper conjugation is a temporary effect

(iii) Fractional distillation is used to separate two liquids from a mixture if the difference in their boiling points is less

(iv) Different compounds are adsorbed on an adsorbent different extents

• ii, iii, iv

• i, ii, iii

• ii, iv

• iii, iv

Identify the correct statements for a ring system to exhibit aromaticity

(i) It must not be planar

(ii) The ring must contain (4n+ 2)Π electrons.

(iii) The ring must be planar.

(iv) It must possess 4n Π electrons.

The correct answer is:

• ii, iv

• i, ii

• i, iv

• ii, iii

Identify, from the following, the diamagnetic, tetrahedral complex

• [Ni(Cl)₄]^2-

• [Co(C₂O₄)₃]^3-

• [Ni(CN)₄]^2-

• [Ni(CO)₄]

Which of the following forms holes in the ozone layer?

• CO

• SO₂

• CO₂

• CF₂Cl₂

To prepare XeF₆. Xe and F₂ are mixed at 573 K and 60-70 bar in the ratio of

• 20:1

• 1:5

• 5:1

• 1:20

Which one of the following solutions of compounds show highest osmotic pressure?[AB, AB₂,A₂B₃ are ionic compounds]

• 5.0 M urea i= 10 and temperature is 67°C

• 1.5M A₂B₂ type i= 41 temperature is 27°C

• 3.0 M AB type i= 16 and temperature is 27°C

• 2.5 M AB₂ type i = 2.5 and temperature is 57°C.

In which of the following reactions, hydrogen is liberated?

$$\begin{gathered} \left(\mathrm{i}\right) \mathrm{Al}\left(\mathrm{s}\right) + \mathrm{HCl}\left(\mathrm{aq}\right) \to \\ \left(\mathrm{ii}\right) \mathrm{Al} \left(\mathrm{s}\right) +\hspace{0.17em}\mathrm{NaOH}\left(\mathrm{aq}\right)\hspace{0.17em}\to \\ \left(\mathrm{iii}\right) {\mathrm{NaBH}}_4 + {\mathrm{I}}_2 \to \end{gathered}$$

• i, ii

• ii, iii

• i,iii

• i, ii, iii