Class 12th

When 9.45g of ClCH₂COOH is added to 500ml. of water, its freezing point drops by 0.5°C. The dissociation constant of ClCH₂ COOH is x * 10^-3. The value of x is__________ (Rounded off to the nearest integer)

$\left[k_{f\left(H_{2}O\right)}=1.86Kkgmo{l}^{-1}\right]$         

Emf of the following cell at 298 K in V is x * 10^-2.

$Zn\left|Z{n}^{2+}\left(0.1M\right)\right|\left|A{g}^{+}\left(0.01M\right)\right|Ag$

The value of x is………… (Rounded off to the nearest integer)

$\left[Given:E_{Z{n}^{2+}/Zn}^0=-0.76V;E_{A{g}^{+}/Ag}^0=+0.80V;\frac{2.303RT}{F}=0.059\right]$

The number of stereoisomers possible for ${\left[Co{\left(ox\right)}_2\left(Br\right)\left(N{H}_3\right)\right]}^{2-}$  is…………

[ox = oxalate]

If the activation energy of a reaction is 80.9 kJ mol^-1, the fraction of molecules at 700K, having enough energy to react to form products, is e^-x. The value of x is………. (Rounded-off to the nearest integer).

[use R = 8.31 J K^-1 mol^-1]

When 12.2g of benzoic acid is dissolved in 100g of water, the freezing point of solution was found to be -0.93°C $\left[K_f(H_{2}O=1.86Kkgmo{l}^{-1}\right].$  The number (n) of benzoic acid molecules associated (assuming 100% association) is…………,

The stepwise formation of ${{\left[Cu{\left(N{H}_3\right)}_4\right]}^2}^{+}$  is given below:

$C{u}^{2+}+N{H}_3\stackrel{k_1}{?}{\left[Cu\left(N{H}_3\right)\right]}^{2+}$            

${\left[Cu\left(N{H}_3\right)\right]}^{2+}+N{H}_3\stackrel{k_2}{?}{\left[Cu{\left(N{H}_3\right)}_2\right]}^{2+}$        

  ${\left[Cu{\left(N{H}_3\right)}_2\right]}^{2+}+N{H}_3\stackrel{k_3}{?}{\left[Cu{\left(N{H}_3\right)}_3\right]}^{2+}$          

${\left[Cu{\left(N{H}_3\right)}_3\right]}^{2+}+N{H}_3\stackrel{k_4}{?}{\left[Cu{\left(N{H}_3\right)}_4\right]}^{2+}$            

The value of stability constants k₁, k₂, k₃ and k₄ are  $10^4,1.58*10^3,5*10^{2}and10^2$ respectively.

The overall equilibrium constants for dissociation of   ${\left[Cu{\left(N{H}_3\right)}_4\right]}^{2+}isx*10^{-12}.$ The value of x is________ (Rounded off to the nearest integer)

In mildly alkaline medium, thiosulphate ion is oxidized by   $Mn{O}_4^{-}$ to “A”. The oxidation state of sulphur in 'A' is………….

The number of octahedral voids per lattice site in a lattice is………. (Rounded off to the nearest integer)

The average S – F bond energy in kJ mol^-1 of SF₆ is………… (Rounded off to the nearest integer) [Given : The values of standard enthalpy of formation of SF₆(g), S(g) and F(g) are – 1100, 275 and 80 kJ mol^-1 respectively.]

Number of amphoteric compounds among the following is___________.