Peptization is a process of:
Precipitating colloidal particles.
Purifying colloidal particles.
Dispersing the precipitate into a colloidal state.
None of the above.
Which acts as poison for Pd-charcoal in lindlar's catalyst ?
BaSO4
Quiniline
Both 1. and 2.
None of these
Electrolyte that is least effective in causing coagulation of +ve ferric hydroxide sol is -
KBr
K2SO4
K2CrO4
K3[Fe(CN)6]
Platinized asbestos used as a catalyst in the manufacture of H2SO4 is an example of:
heterogeneous catalyst
auto-catalyst
homo-catalyst
induced catalyst
In a reversible reaction, a catalyst:
increases the rate of the forward reaction only
increases the rate of the forward reaction to a greater extent than that of the backward reaction
increases the rate of the forward reaction and decreases that of the backward reaction to the different extent
increases the rate of the forward and backward reactions equally
Gas masks containing activated charcoal remove poisonous gases from the atmosphere, and act on the principle of:
Adsorption
Absorption
Sorption
All of these
Tanning of leather is:
coloring of leather by chemicals
drying process to make the leather hard
polishing of leather to make it look attractive
coagulative hardening of the leather by chemicals
When sulphur sol is evaporated solid sulphur is left. On mixing with water no colloidal sol is formed. Sulphur sol is:
hydrophilic
hydrophobic
reversible
lyophilic
The Critical Micelle Concentration (CMC) is:
The concentration at which micellization starts
The concentration at which true solution is formed
The concentration at which one molar electrolyte is present per 1000 g of solution
The concentration at which solute and solution from equilibrium
On adding 1 mL solution of 10% NaCl to 10 mL gold solution in the presence of 0.25 g of starch, the coagulation is just prevented. Starch has the gold number equal to:
0.25
2.5
250
0.025
Sol that is not lyophilic colloid is -
Milk
Gum
Fog
Blood
Hardy-Schulze rule states that:
non-electrolytes have better coagulating action on colloids than electrolytes
sols are coagulated by effective ions whose charge is opposite to that of sol and the ions of higher charge are much more effective than the ions of lower charge
charge of the ions has no effect on the coagulation of a sol
sols are coagulated only by those ions whose charge is similar to that of the sol
An example of intrinsic colloid is:
As2S3 sol
Fe(OH)3 sol
egg albumin
Au sol
Tails of comets are visible due to:
Tyndall effect
Reflection
Brownian motion
None of the above
Bleeding is stoped by the application of ferric chloride. This is because :
the blood starts flowing in the opposite direction
the blood reacts and a solid is formed which seals the blood vessel
the blood is coagulated and the blood vessel are sealed
the ferric chloride seals the blood vessel
The Brownian movement occurs in:
Colloidal solution.
True solution.
Suspension having size <500 mμ.
All of the above.
A dust storm is:
Dispersion of solid in gas
Dispersion of a gas in solid
Dispersion of solid in solid
Dispersion of a gas in liquid
Which is not a colloid?
Chlorophyll
Egg white
Ruby glass
Chemisorption is:
multimolecular in nature
often highly specific and directional
not very specific
The catalyst used in the lead-chamber process of sulphuric acid is:
platinum
nitric oxide
nickel
vanadium pentoxide
Medicines are more effective if they are used in:
Colloidal state
Solid-state
Solution state
Hydrolysis of maltose (C12H22O11) by maltase gives:
glucose
fructose
both 1 and 2
none of these
Hydrolysis of cane-sugar is catalysed by:
H+
mineral acids
enzymes
all of these
Which is not shown by sols?
Flocculation
Paramagnetism
Detergent action of synthetic detergents is due to their:
interfacial area
high molar mass
ionization
emulsifying properties
The name aquadag refers for:
Cu in water sol.
Pt in water sol.
Graphite in water sol.
Addition of FeCl3 to K4[Fe(CN)6] in dilute and cold solution gives:
Prussian blue sol.
Fe4[Fe(CN)6]3 sol.
Positive sol.
Among the electrolytes Na2SO4, CaCl2, Al2(SO4)3 and NH4Cl, the most effective coagulating agent for Sb2S3 sol is :
Na2SO4
CaCl2
Al2(SO4)3
NH4Cl
A negatively charged suspension of clay in water needs for precipitation the minimum amount of:
Aluminium chloride.
Potassium sulphate.
Sodium hydroxide.
Hydrochloric acid.
The arsenious sulphide sol has negative charge. The maximum coagulationg power for precipitating it is of :
0.1 N Zn(NO3)2
0.1 N Na3PO4
0.1 N ZnSO2
0.1 N AlCl3
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