Identify the incorrect statement.

$Fe(OH)_3$ sol and gold sol are positively and negatively charged,respectively. Which of the following statements is incorrect?

When an excess of a very dilute aqueous solution of $KI$ is added to a very dilute aqueous solution of silver nitrate,the colloidal particles of silver iodide are associated with the Helmholtz double layer in the form of:

The gold numbers of protective colloids $A, B, C,$ and $D$ are $0.50, 0.01, 0.10,$ and $0.005$ respectively. The correct order of their protective power is:

The volume of a colloidal particle,$V_C$,as compared to the volume of a solute particle in a true solution,$V_S$,could be:

$A$ system of cellulose dispersed in alcohol is known as a ...... .