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

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

19.

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