The compound that acts as an inhibitor for knocking in the combustion of petrol is:
1. (C2H5)4Pb
2. Ni(CO)4
3. Both (1) and (2)
4. None of the above.
Butter is a colloid form in which:
1. fat is dispersed in solid casein
2. fat globules are dispersed in water
3. water is dispersed in fat
4. suspension of casein is in water
Milk can be preserved by adding a few drops of?
1. Formic acid solution
2. Formaldehyde solution
3. Acetic acid solution
4. Acetaldehyde solution
Silver iodide is used for producing artificial rain because AgI is:
1. Easy to spray at high altitudes.
2. Easy to synthesize.
3. Having crystal structure similar to ice.
4. Insoluble in water.
A small amount of phosphoric acid can be used to prevent H2O2 decomposition. This an example of?
1. Neutralization
2. Negative catalysis
3. Positive catalysis
4. Catalytic poisoning
Emulsions of polyvinylacetate are used in:
1. polishes
2. latex paints
3. fire works
4. rayons
Given below are three process:
a. Emulsification
b. Adsorption
c. Absorption
The process of froth flotation and chromatography is based on:
1. a & b
2. b & c
3. a & c
4. None of the above
In adding 1 mL of solution of 10 % NaCl to 10 mL of gold solution in the presence of 0.25 g of starch, the coagulation is just prevented. Starch has a gold number equal to:
1. 0.25
2. 2.5
3. 250
4. 0.025
What is a solution that isn't a lyophilic colloid?
1. Milk
2. Gum
3. Fog
4. Blood
The surface tension of lyophilic sols is:
1. Lower than H2O
2. More than H2O
3. Equal to H2O
4. None of the above.
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
At 400 K, the energy of activation of a reaction is decreased by 0.8 kcal in the presence of a catalyst. As a result, the rate will be:
1. | Increased by 2.71 times. | 2. | Increased by 1.18 times. |
3. | Decreased by 2.72 times. | 4. | Increased by 6.26 times. |