$$ \wedge _m^ \circ $$ for NaCl, HCl and NaA are 126.4, 425.9 and 100.5 S cm² mol^–1, respectively. If the conductivity of 0.001 M HA is-

5 $$ \times $$ 10^–5 S cm^–1, degree of dissociation of HA is -

The major product of the following reaction is –

The compound that is NOT a common component of photochemical smog is :

The combination of plots which does not represent isothermal expansion of an ideal gas is –