The simplest way to check whether a system is colloidal is by
electrodialysis
finding out particle size
Tyndall effect
Brownian movement
Which statement is true?
The adsorption of H2 by platinum black is known as sorption
The adsorption of H2 by charcoal is known as occlusion
The adsorption of H2 by platinum black is known as occlusion
The absorption of H2 by charcoal is known as chemisorption.
In the case of auto catalysis
product catalysis
solvent catalysis
reactant catalysis
heat produced in the reaction catalysis
Which among the following statements is false?
The adsorption may be monolayered or multilayered
Particle size of adsorbent will not affect the amount of adsorption
Increase of pressure increases amount of adsorption
Increase of temperature may decrease the amount of adsorption
Which of the following is not a characteristic of chemisorption?
H is of the order of 400 kJ
Adsorption is irreversible
Adsorption may be multimolecular layer
Adsorption is specific
The concentration of electrolyte required to coagulate a given amount of As2S3 solution is minimum in the case of
magnesium nitrate
potassium nitrate
potassium sulphate
aluminium nitrate
D.
aluminium nitrate
As2S3 solution is a negative solution due to preferential adsorption of S2- ions. [As2S3]S2-, hence, a cation is needed to coagulate it. According to Hardy Schulze law, aluminium nitrate will be the most efficient to coagulate it as it gives the most valent aluminium ion (Al3+), hence, it is required in minimum amount (i.e. coagulation value is least for Al(NO3)3.
In the manufacture of sulphuric acid by contact process, Tyndall box is used to
filter dust particles
remove impurities
convert SO2 to SO3
test the presence of dust particles
Pick out the statement which is not relevant in the discussion of colloids
sodium aluminium silicate is used in the softening of hard water
potash alum is used m shavmg rounds and as a styptic in medicine
artificial rain is caused by throwing electrified sand on the clouds from an aeroplane
deltas are formed at a place where the river pours its water into the sea
The diameter of colloidal particles range from
10-6m to 10-9m
10-9m to 10-12m
103m to 10-3m
10-3m to 10-6 m