Which acts as poison for Pd-charcoal in lindlar's catalyst ?
(a) BaSO4
(b) Quiniline
(c) Both (a) and (b)
(d) 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 to remove poisonous gases from atmosphere acts on the principle of:
(1) Adsorption
(2) Absorption
(3) Sorption
(4) All of these
Tanning of leather is:
(1) Colouring 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:
(a)hydrophilic
(b)hydrophobic
(c)reversible
(d)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:
(a) As2S3 sol (b) Fe(OH)3 sol
(c) egg albumin (d) 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?
(a) Chlorophyll (b) Egg white
(c) Ruby glass (d) Milk