In a reaction, A + B $\rightleftharpoons$C + D, D, 40% of B has reacted at equilibrium, when 1 mole of A was heated with 1 mole of B in a 10 L closed vessel. The value of K_c is

• 0.44

• 0.18

• 0.22

• 0.36

12.

If the ionc product of Ni(OH)₂ is 1.9× 10^-15, the molar solubility of Ni(OH)₂ in 1.0 M NaOH

• 1.9 × 10^-18 M

• 1.9 × 10^-13 M

• 1.9 × 10^-15 M

• 1.9 × 10^-15 M

Which one of the following elements on doping with germanium, make it a p-type semiconductor?

• Boron

• Selenium

• Arsenic

• Germanium

Which one of the following gives sooty flame on combustion?

• C₂H₄

• CH₄

• C₂H₆

• C₆H₆

What is Z in the following reaction?

${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CO}}_2^{⊝}{\mathrm{Na}}^{\oplus }\stackrel{\mathrm{NaOH}/\mathrm{CaO}}{\to } \mathrm{Z}$

• propane

• n-butane

• ethane

• ethyne

What are X and Y in the following reaction?

${\mathrm{CF}}_2{\mathrm{Cl}}_2 \stackrel{\mathrm{UV}}{\to } \mathrm{X} + \mathrm{Y}$

• CF₂Cl, Cl

• C₂F₄, Cl₂

• CFCl₂, F

• CCl₂, F₂

Which one of the following elements reacts with steam?

• C

• Ge

• Si

• Sn

Temporary hardness of water is removed in Clark's process by adding

• caustic soda

• calgon

• borax

• lime

Which one of the following correctly represents the variation of electronegatrvity (EN) with atomic number (Z) of group 13 elements?

Which one of the following is more readily hydrolysed by S_N1 mechanism?

• (C₆H₅)₂C(CH₃)Br

• C₆H₅CH₂Br

• C₆H₅CH(CH₃)Br

• (C₆H₅)₂CHBr