Surface chemistry practice · Mixed difficulty

$50 \mathrm{ml}$ of $\mathrm{Fe}(\mathrm{OH})_3$ sol is completty coagulated by $50 \mathrm{ml}$ of $0.2 \mathrm{M} \mathrm{KBr}$. Coagulation value is

Blue colour of the sky is due to

The Gold number of four protective colloids A, B, C and D are 0.03, 0.003, 10 and 30 resp. protective power of these colloids will be in the order

Which one is hydrophobic in nature?

Platinum is used as a catalyst in :

The arsenioussulphide sol has negative charge. The maximum coagulating power for precipitating it is of :

Which of the following can reduce decomposition of $\mathrm{H}_{2} \mathrm{O}_{2}$ on exposure to light

Using very little soap while washing clothes, does not serve the purpose of cleaning of clothes, because:

The catalyst iron, employed in the Haber’s process, contains molybdenum, the function of which is :

Amongst the following statements regarding adsorption, those that are valid are:
(A) $\Delta \,H$ becomes less negative as adsorption proceeds.
(B) On a given adsorbent, ammonia is adsorbed more than nitrogen gas.
(C) On adsorption, the residual force acting along the surface of the adsorbent increases.
(D) With increase in temperature, the equilibrium concentration of adsorbate increases.

Identify the gas which is readily adsorbed by activated charcoal

Which of the following is not correct?

Plot of $\log \frac{x}{m}$ against $\log p$ is a straight line inclined at an angle of $45^\circ$. When the pressure is 0.5 atm and Freundlich parameter, $k$ is 10, the amount of solute adsorbed per gram of adsorbent will be (log 5=0.6990)

Washing soap can be prepared by saponifying alkali with oil of :

The velocity of oxidation of oxalic acid by acidified $\mathrm{KMn}{\mathrm{O}_4}$ increase as the reaction progress. It is an example of

Catalysts are generally used in finely divided state because

In Freundlich adsorption isotherm, the value of $1/n$ is

Which of the following forms cationic micelles above certain concentration?

Air can oxidize sodium sulphite in aqueous solution but cannot do so in the case of sodium arsenite. If however, air is passed through a solution containing both sodium sulphite and sodium arsenite then both are oxidized. This is an example of :

For a gas-solid adsorbent system, the adsorption isotherm $\frac{x}{m}=K p^{1 / n}$ is applicable, where $n=5$ in the specified case. Point out the correct statement:

3.6 gram of oxygen is adsorbed on $1.2 \mathrm{~g}$ of metal powder. What volume of oxygen adsorbed per gram of the adsorbent at $1 \mathrm{~atm}$ and $273 \mathrm{~K}$?

Among the following, the false statement is

A colloidal solution always has at least :

Assertion (A): When ${SnO}_2$ is reacted with ${NaOH}$, then its sol. particles are attracted towards cathode.

Reason (R): When ${SnO}_2$ is reacted with ${NaOH}$, then it gives ${SnO}_3^{2-}$ which is absorbed by ${SnO}_2$, so it is negatively charged sol.

The size of colloidal particle is

The example of anionic surfactants is

Assertion (A): ${SO}_2$ gas is easily liquified while ${H}_2$ is difficult to liquify.

Reason (R): ${SO}_2$ has low critical temperature while ${H}_2$ has high critical temperature.

A detergent $\left(\mathrm{C}_{12} \mathrm{H}_{25} \mathrm{SO}_4^{-} \mathrm{Na}^{+}\right)$solution becomes a colloidal sol at a concentration of $10^{-3} \mathrm{M}$. On an average $10^{13}$ colloidal particles are present in $1 \mathrm{~mm}^3$. What is the average number of ions which are contained by one colloidal particle (micelle)?

The density of gold is $19 \mathrm{~g} / \mathrm{cm}^3, 1.9 \times 10^{-3} \mathrm{~g}$ of gold is dispersed in one litre of water to give a sol having spherical gold particles of radius $10.5 \mathrm{~nm}$.
The gold particles are occupying $50 \%$ of the available space. The number of gold particles per $\mathrm{mm}^3$ is about $10^n$. Find the value of $n$.

In whipped cream, the dispersed phase and dispersion medium respectively are