The cotterells precipitator is used to :
1. neutralize charge on carbon particles in air in smoke
2. coagulate carbon atoms of smoke
3. bring in cataphoresis in carbon particles
4. all of the above
A liquid aerosol is a colloidal system of:
1. a liquid dispersed in a solid
2. a liquid dispersed in a gas
3. a gas dispersed in a liquid
4. a solid dispersed in a gas
A negative catalyst or inhibitor is one:
1. which retards the rate of reaction
2. takes the reaction in forward direction
3. promotes the side reaction
4. None of the above
Which of the following does not form anionic micelle?
1. C12H25COONa
2. C12H25SO4Na
3. C12H25SO3Na
4. C12H25(NH3)3Cl
Clouds, mist, fog and aerosols are colloidal solution of:
1. solid in a gas
2. gas in a solid
3. liquid in a gas
4. gas in a liquid
The index for the Gold number is:
1. Protective power of lyophilic colloid.
2. Purity of gold.
3. Metallic gold.
4. Electroplated gold.
Which is an emulsion?
1. Boot polish
2. Lipstick
3. Shampoo
4. All of these
Milk contains a protein that is very good for health. The protein is:
1. caffeine
2. calciferol
3. keratin
4. casein
The charge on As2S3 sol is caused by the adsorption of:
1. H+
2. OH-
3.
4. S2-
Which acts as poison for Pd-charcoal in lindlar's catalyst ?
1. BaSO4
2. Quiniline
3. Both 1. and 2.
4. None of these
In a reversible reaction, a catalyst:
1. increases the rate of the forward reaction only
2. increases the rate of the forward reaction to a greater extent than that of the backward reaction
3. increases the rate of the forward reaction and decreases that of the backward reaction to the different extent
4. 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:
1. Adsorption
2. Absorption
3. Sorption
4. All of these
Tanning of leather is:
1. coloring of leather by chemicals
2. drying process to make the leather hard
3. polishing of leather to make it look attractive
4. 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:
1. hydrophilic
2. hydrophobic
3. reversible
4. lyophilic
The Critical Micelle Concentration (CMC) is:
1. The concentration at which micellization starts
2. The concentration at which true solution is formed
3. The concentration at which one molar electrolyte is present per 1000 g of solution
4. The concentration at which solute and solution from equilibrium
Hardy-Schulze rule states that:
1. non-electrolytes have better coagulating action on colloids than electrolytes
2. 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
3. charge of the ions has no effect on the coagulation of a sol
4. sols are coagulated only by those ions whose charge is similar to that of the sol
An example of intrinsic colloid is:
1. As2S3 sol
2. Fe(OH)3 sol
3. egg albumin
4. Au sol
Bleeding is stoped by the application of ferric chloride. This is because :
1. the blood starts flowing in the opposite direction
2. the blood reacts and a solid is formed which seals the blood vessel
3. the blood is coagulated and the blood vessel are sealed
4. the ferric chloride seals the blood vessel
Which is not a colloid?
1. Chlorophyll
2. Egg white
3. Ruby glass
4. Milk
Chemisorption is:
1. multimolecular in nature
2. reversible
3. often highly specific and directional
4. not very specific
Medicines are more effective if they are used in:
1. Colloidal state
2. Solid-state
3. Solution state
4. None of the above
Which is not shown by sols?
1. Adsorption
2. Tyndall effect
3. Flocculation
4. Paramagnetism
Detergent action of synthetic detergents is due to their:
1. interfacial area
2. high molar mass
3. ionization
4. emulsifying properties
Among the given options, which element is the minimum required for precipitation of a negatively charged suspension of clay in water?
1. Aluminium chloride.
2. Potassium sulphate.
3. Sodium hydroxide.
4. Hydrochloric acid.
The arsenious sulphide sol has negative charge. The maximum coagulationg power for precipitating it is of :
1. 0.1 N Zn(NO3)2
2. 0.1 N Na3PO4
3. 0.1 N ZnSO2
4. 0.1 N AlCl3
An emulsifier is a substance that:
1. Homogenesis the emulsion
2. Stabilizes the emulsion
3. Retards the dispersion of liquid in the liquid
4. Coagulates the emulsion
How is the flocculation value expressed?
1. Millimole per litre.
2. Mole per litre.
3. Gram per litre.
4. Mole per millilitre.
Which is an emulsifier?
1. Soap
2. Oil
3. NaCl
4. Water
The capacity of an ion to coagulate a colloidal solution depends on:
1. its shape
2. amount of its charge
3. the sign of charge
4. both amount and sign of the charge
Lyophobic colloids are:
1. Reversible colloids
2. Irreversible colloids
3. Protective colloids
4. Gum, and proteins
The decomposition of H2O2 may be checked by adding a small quantity of phosphoric acid. This is an example of:
(1) neutralization
(2) negative catalysis
(3) positive catalysis
(4) catalytic poisoning
Which of the following is not applicable to chemisorption?
1. Its heat of adsorption is high
2. It takes place at high temperature
3. It is reversible
4. It forms unimolecular layer
As2S3 sol is
1. possible colloid
2. negative colloid
3. neutral colloid
4. none of the above
At the critical micelle concentration (CMC) the surfactant molecule
1. deccompose
2. dissociate
3. associate
4. become completely soluble
Which one has the highest coagulation power?
1. K+
2. Ca++
3. Al+++
4. Sn4+
The charge on As2S3 sol is due to to the adsorbed:-
(1) H+
(2) OH-
(3) O-2
(4) S-2
The most suitable electrolyte for the coagulation of arsenic sulphide will be:-
1. AlCl3
2. BaCl2
3. NaCl
4. KCl
According to Freundlich adsorption isotherm, which of the following is correct:-
(1)
(2)
(3)
(4) All are correct for different ranges of pressure
Which one of the following statements is not correct?
(1) Catalyst does not initiate any reaction
(2) The value of equilibrium constant is changed in the presence of a catalyst in the reaction equilibrium
(3) Enzymes catalyse mainly biochemical reaction
(4) Coenzymes increase the catalytic activity of enzyme
The coagulation values in millimoles per liter of the electrolytes used for the coagulation of As2S3 are given below
I. (NaCl) =52 II. (BaCl2) =0.69
III. (MgSO4) = 0.22
The correct order of their coagulating power is
(1) I>II>III
(2) II>I>III
(3) III>II>I
(4) III>I>II
The addition of a catalyst during a chemical reaction alters which of the following quantities?
(1) Internal energy
(2) Enthalpy
(3) Activation energy
(4) Entropy
Which one of the following characteristics is associated with adsorption?
(1) G, H and S all are negative
(2) G and H are negative but S is positive
(3) G and S are negative but H is positive
(4) G is negative but H and S are positive
Fog is a colloidal solution of:-
1. Gas in liquid
2. Solid in gas
3. Gas in gas
4. Liquid in gas
The protecting power of lyophilic colloidal sol is expressed in terms of
1. coagulation value
2. gold number
3. critical micelle concentration
4. oxidation number
The stabilization of the dispersed phase in a lyophobic sol is due to
(1) The viscosity of the medium
(2) The surface tension of the medium
(3) Liking for the medium
(4) The formation of an electrical layer between the two phases