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.]

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

Zn|Zn²⁺(0.1 M)||Ag⁺ (0.01 M)|Ag

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

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

The pH of ammonium phosphate solution, if pk_a of phosphoric acid and pk_b of ammonium hydroxide are 5.23 and 4.75 respectively, is ___________.

The number of stereoisomers possible for [Co(ox)₂(Br)(NH₃)]^2$$-$$ is ___________. [ox = oxalate]