Tag: surface chemistry

Quizzes (6) Questions (144)

Questions Related to surface chemistry

Multiple choice applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

Application of adsorption chromatography is/are _________.

  1. separation of relatively non polar, water insoluble compounds

  2. seperation of isomers

  3. purification of antibody fragments

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Adsorption chromatography has many applications. Generally, it is used for determining the concentration of a compound (or its purity), separating out a mixture into individual componentsseperation of isomers, and identifying what is in a mixture and seperate on the basis of solubility also. There are three main types of adsorption chromatography - column, thin layer, and gas-solid.

Multiple choice applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

Adsorption column chromatography has been used for :

  1. isolation and purification of vitamins and hormones

  2. examination of vegetable oil and pharmaceutical preparations

  3. used as indicator

  4. all of the above
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

Column chromatography is used for isolation and purification of vitamins and hormones and for the examination of vegetable oil and pharmaceutical preparations.

Multiple choice applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

Which of the following is most favourable for vander waals  adsorption?

  1. high pressure and high temperature

  2. low pressure and low temperature

  3. low pressure and high temperature

  4. high pressure and low temperature
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Physisorption is Vanderwaals adsorption, it occurs at high pressure and low temperature conditions.

Multiple choice enzymes and catalysts catalysis adsorption and colloids surface chemistry chemistry adsorption theory of heterogeneous catalysis

What does a catalyst do?

  1. Alter the state of equilibrium.

  2. Decreases the activation energy.

  3. Increases collision frequency.

  4. Increases the average kinetic energy of reacting species.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Catalyst is a substance, which lowers the activation energy of reaction because it provides an alternate pathway for reaction. Also, it increases backward and forward reaction to the same extent. Due to this lower activation energy, equilibrium is attained faster.

Multiple choice enzymes and catalysts catalysis adsorption and colloids surface chemistry chemistry adsorption theory of heterogeneous catalysis

Which of the following is the best way to speed up a chemical reaction?

  1. Make an effort to concentrate the reactants as best as possible

  2. Add a catalyst

  3. Cool the reaction down

  4. Increase the pressure on the system
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
5 ways to increase the reaction rate :
1. The nature of the reactants: A reaction between two gases would be faster than a reaction between to liquids or two solids.
2. Temperature:  The heat causes the particles to move quickly, and due to the Collision Theory,  the reaction will occur faster.
3. Concentration: The higher the concentration of a reactant, the quicker the reaction will occur. 
4. Surface Area: The more the particles are exposed, the faster it is for the other reactant to collide into the particles, meaning the reaction rate will increase.
5. Catalysts: Catalysts are substances that increase the rate of reaction by speeding up the reaction without being used up in the reaction.
Adding catalyst can most effectively speed up the chemical reaction. 
Multiple choice enzymes and catalysts catalysis adsorption and colloids surface chemistry chemistry adsorption theory of heterogeneous catalysis

Competitive inhibition is reversible.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Competitive Inhibitors belong to the category of enzymes known as reversible inhibitors. Reversible inhibitors dissociate the enzyme-inhibitor complex as soon as possible.

This Chemical reaction can be reversed by increasing concentration of substrate. These process continuously takes place as $E + S \rightarrow ES \rightarrow E + P$