31.

Lithium metal crystallises in a body centred cubic crystal. If the length of the side of the unit cell lithium is 351 pm, the atomic radius of the lithium will be 

• 240.8 pm

• 151.8 pm

• 75.5

• 75.5

For the reaction, N₂ + 3H₂ → 2NH₃, If  the value of  would be

• 3 x 10^-4 mol L^-1 s^-1

• 4 x 10^-4 mol L^-1s^-1

•  6 x 10^-4 mol L^-1s^-1

•  6 x 10^-4 mol L^-1s^-1

Out of TiF₆^2-, CoF₆^3-, Cu₂Cl₂ and NiCl₄^2- (Z of Ti = 22, Co= 27, Cu = 29, Ni =28) the colourless species are

• TiF₆^2- and CoF₆^3-

• Cu₂Cl₂ and NiCl₄^2-

• TiF₆^2- and Cu₂Cl₂

• TiF₆^2- and Cu₂Cl₂

Which of the following compound will exhibit cis-trans (geometrical) isomerism? 

• 2-butene

• Butanol

• 2-butyne

• 2-butyne

The values of ΔH and ΔSfor the reaction, C_(graphite) + CO₂  → 2 CO (g) are 170 kJ and 170 JK^-1 respectively. This reaction will be spontaneous at 

• 710 K

• 910 K

• 1110 K

• 1110 K

In the reaction,


The rate of appearance of bromine (Br)₂ is related to rate of disappearnace of bromide ions as following

The stability of +1 oxidation state increases in the sequence 

• Al < Ga <In < Tl

• Tl < In <Ga< Al

• In < Tl < Ga < Al

• In < Tl < Ga < Al

A 0.0020 m aqueous solution  of an ionic compound Co(NH₃)₅(NO₂)Cl freezes at -0.00732^o C . Number of moles of ions which 1 mol of ionic compound produces on being dissolved in water will be (k_f = - 1.86^o C/m)

• 2

• 3

• 4

• 4

Which of the following reactions is an example of nucleophilic substitution reaction?

• RX + KOH → ROH + KX

• 2RX + 2Na → R- R 

• RX + H₂ → RH + HX

• RX + H₂ → RH + HX

Which one of the following is employed as a tranquilizer?

• Equanil

• Naproxen

• Tetracycline

• Tetracycline