191. Mixing of positively charged colloidal solution with negatively charged colloidal solution brings _________. The decreasing order of coagulating power of $$N{a^ + },B{a^{2 + }}$$ and $$A{l^{3 + }}$$ for negatively charged colloidal solution is __________.
A
mutuaI coagulation, $$N{a^ + } > B{a^{2 + }} > A{l^{3 + }}$$
B
mutual coagulation, $$A{l^{3 + }} > B{a^{2 + }} > N{a^ + }$$
C
peptization, $$N{a^ + } > B{a^{2 + }} > A{l^{3 + }}$$
D
peptization, $$A{l^{3 + }} > B{a^{2 + }} > N{a^ + }$$
Answer :
mutual coagulation, $$A{l^{3 + }} > B{a^{2 + }} > N{a^ + }$$
192.
For the graph below, select correct order of temperature?
A
$${T_1} > {T_2} > {T_3}$$
B
$${T_2} > {T_3} > {T_1}$$
C
$${T_3} > {T_2} > {T_1}$$
D
$${T_1} = {T_2} = {T_3}$$
Answer :
$${T_3} > {T_2} > {T_1}$$
193. Which of the following statements is not correct about physisorption?
A
It is a reversible process.
B
It requires less heat of adsorption.
C
It requires activation energy.
D
It takes place at low temperature.
Answer :
It requires activation energy.
194. The heat evolved in chemisorption lies in the range ( in $$kJ/mol$$ ) of :
A
80 to 240
B
20 to 40
C
40 to 80
D
20 to 100
Answer :
80 to 240
195. Which of the following forms cationic micelles above certain concentration?
A
Sodium ethyl sulphate
B
Sodium acetate
C
Urea
D
Cetyl trimethyl ammonium bromide
Answer :
Cetyl trimethyl ammonium bromide
196. Which one of the sols acts as protective colloid ?
A
$$A{s_2}{S_3}$$
B
$${\text{Gelatin}}$$
C
$$Au$$
D
$$Fe{\left( {OH} \right)_3}$$
Answer :
$${\text{Gelatin}}$$
197. Butter is a colloid formed when
A
fat is dispersed in water
B
fat globules are dispersed in water
C
water is dispersed in fat
D
None of the these
Answer :
water is dispersed in fat
198. Lyophilic sols are more stable than lyophobic sols because :
A
the colloidal particles have positive charge
B
the colloidal particles have negative charge
C
the colloidal particles are solvated
D
there is strong electrostatic repulsion between the colloidal particles
Answer :
the colloidal particles are solvated
199. The oxide of nitrogen which acts as a catalyst in lead chamber process is
A
$$NO$$
B
$$N{O_2}$$
C
$${N_2}{O_4}$$
D
$${N_2}{O_5}$$
Answer :
$$NO$$
200. On adding $$AgN{O_3}$$ solution to $$KI$$ solution, a negatively charged colloidal sol will be formed in which of the following conditions?
A
$$100\,mL\,\,{\text{of}}\,\,0.1\,M\,AgN{O_3}$$ $$ +\, 100\,mL\,\,{\text{of}}\,\,0.1\,M\,KI$$
B
$$100\,mL\,\,{\text{of}}\,\,0.1\,M\,AgN{O_3}$$ $$ + \,50\,mL\,\,{\text{of}}\,\,0.2\,M\,KI$$
C
$$100\,mL\,\,{\text{of}}\,\,0.2\,M\,AgN{O_3}$$ $$ + \,100\,mL\,\,{\text{of}}\,\,0.1\,M\,KI$$
D
$$100\,mL\,\,{\text{of}}\,\,0.1\,M\,AgN{O_3}$$ $$ + \,100\,mL\,\,{\text{of}}\,\,0.15\,M\,KI$$
Answer :
$$100\,mL\,\,{\text{of}}\,\,0.1\,M\,AgN{O_3}$$ $$ + \,50\,mL\,\,{\text{of}}\,\,0.2\,M\,KI$$