For the following Assertion and Reason, the
correct option is
Assertion (A): When Cu (II) and sulphide ions
are mixed, they react together
extremely quickly to give a
solid.
Reason (R): The equilibrium constant of
Cu²⁺(aq) + S^2–(aq) ⇌ CuS(s) is
high because the solubility
product is low.