How many of the following are true solutions?
$I :$ Urea solution,
$II :$ Gelatin,
$III :$ Glucose solution,
$IV :$ $NaCl$ solution,
$V :$ Butter,
$VI :$ Blood

The disease kala azar is caused by

In each of four separate beakers $(I, II, III, IV)$,$X \ mL$ of $y \ M \ Fe_2O_3 \cdot xH_2O$ colloidal solution is present. Equal volume and equal concentration of $KCl, K_4[Fe(CN)_6], K_3PO_4$ and $K_2SO_4$ were added into $I, II, III$ and $IV$ respectively. The efficiency of precipitation in these beakers follows the order:

Which of the following nanomaterials has all three dimensions $< 100 \text{ nm}$?

$As_2S_3$ sol has a negative charge. The maximum coagulation power will be of:

In which of the following is the Tyndall effect not observed?