Methylene blue, from its aqueous solution, is adsorbed on activated charcoal at 25^oC. For this process, the correct statement is

Benzene and naphthalene form an ideal solution at room temperature. For this process, the true statement(s) is(are)

Sulphide ores are common for the metals

KI in acetone undergoes S_N2 reaction with each of P, Q, R and S. The rates of the reaction vary as