A closed tank has two compartments $$A$$ and $$B,$$ both filled with oxygen (assumed to be ideal gas). The partition separating the two compartments is fixed and is a perfect heat insulator (Figure $$1.$$). If the old partition is replaced by a new partition which can slide and conduct heat but does NOT allow the gas to leak across (Figure $$2$$), the volume (in $${m^3}$$) of the compartment A after the system attains equilibrium is ______________.

In 1 L saturated solution of AgCl [K_sp(AgCl) = 1.6 $$\times$$ 10^-10], 0.1 mol of CuCl [K_sp(CuCl) = 1.0 $$\times$$ 10^-6] is added. The resultant concentration of Ag⁺ in the solution is 1.6 $$\times$$ 10^-x. The value of "x" is

Amongst the following the total number of compounds whose aqueous solution turns red litmus paper blue is
KCN, K₂SO₄, (NH₄)₂C₂O₄, NaCl, Zn(NO₃)₂, FeCl₃, K₂CO₃, NH₄NO₃ and LiCN