Which of the following ions can cause coagulation of proteins?

Assertion : Aqueous gold colloidal solution is red in colour.
Reason : The colour arises due to scattering of light by colloidal gold particles.

The coagulation of $10 \, mL$ of gold sol is prevented by the addition of $0.025 \, g$ of starch to it before adding $1 \, mL$ of $10 \% \, NaCl$ solution. The gold number of starch is .............

Which of the following statements is true for a lyophilic sol?

The qualitative sketches $I$,$II$,and $III$ given below show the variation of surface tension with molar concentration of three different aqueous solutions of $KCl$,$CH_3OH$,and $CH_3(CH_2)_{11}OSO_3^{-}Na^{+}$ at room temperature. The correct assignment of the sketches is

What is the typical range for the $CMC$ (Critical Micelle Concentration) of soap in aqueous solution?