The most adsorbed gas on activated charcoal is

Which of the following is correct about lyophilic sols?

The function of gum arabic in the preparation of Indian ink is

Which of the following are the characteristics of chemisorption ?

1. High heat of adsorption

2. Irreversibility

3. Low activation energy

Select the correct answer using the code given below :

Which of the following relation is correct ?
(i) x/m = constant at high pressure
(ii) x/m = constant xp^1/n (at intermediate pressure)
(iii) x/m = constant xpⁿ (at lower pressure)

What is meant by coagulation of a colloidal solution? Name any method by which coagulation of lyophobic sols can be carried out.

Define the following :
(i) Peptization
(ii) Reversible sols

The action of enzyme is highly specific. Do you agree with this statement? Explain.

Write the reaction in which bismuthmolybdate is used as catalyst. Explain which characteristic of catalyst is shown by this reaction.

(a) What are the two types of emulsions and how do they differ from one another? Give one example of each.
(b) Which one of the following electrolytes is most effective for the coagulation of Fe(OH)₃ sol and why?
NaCl, Na₂ SO₄ , Na₃ PO₄

(a) Which will adsorb more gas, a lump of charcoal or its powder and why?
(b) Describe the preparation of the following colloidal solutions. Name the method used in each case:
(i) Silver sol
(ii) Sulphur sol

Classify colloids where the dispersion medium is water. State their characteristics and write an example of each of these classes.

Radha and Meera are fast friends. They both study in class XII.Radha is a student of science while Meera follows commerce stream. One day, when they were playing, Radha got hurt and started bleeding. Meera took her to house and applied some alum on the cut. The bleeding stopped immediately.
(i)Why bleeding stopped when some alum is applied on the cut?
(ii) What are the values associated with Meera's decision to take Radha to her house and apply alum on her cut?

Reetu is purely vegetarian but her husband Rohit likes non-vegetarian food. He regularly buys nonvegetarian goods (fish, meet, eggs etc.) and store these in fridge. The intermixing of odours creates problem for Reetu. Their daughter Rihana is a student of science. One day Rihana suggested her mother to put some small pieces of charcoal in the fridge as she thinks that this will solve the problem to some extent.
(i) Do you think by putting some small pieces of charcoal in the fridge will solve the problem of intermixing of odours. Give reason for your answer.
(ii) What are the values associated with Rihana's suggestion?

20% of surface sites are occupied by N₂ molecules. The density of surface sites is \(6.023\times { 10 }^{ 14 }\) cm^-2 and total surface area is 1000 cm² . The catalyst is heated to 300 K while N₂ is completely disorbed into a pressure of 0.001 atm and volume 2.46 cm³. Find the active sites occupied by each N₂ molecule.

In an adsorption experiment, a graph between log (x/m) versus log P was found to be linear with a slope of 45^o. The intercept on the log (x/m) axis was found to be 0.310. Calculate the amount of the gas adsorbed per gram of charcoal under a pressure of 0.5 atmosphere.