Chemistry - Online Test
Q1. Which among the following statement is not true for catalyst?
Answer : Option C
Explaination / Solution:
Catalyst does not change the equilibrium constant it only helps in reaching the equilibrium at a faster rate,i.e. it catalyses the forward as well as teh backward reactions to the same extent so that the equilibrium state remains same but is reached earlier.
Q2. Which among the following is an example of sorption?
Answer : Option B
Explaination / Solution:
When chalk is dipped in ink, absorption and adsorption both takes place.
Q3. Above the Critical temperature of carbon dioxide
Answer : Option D
Explaination / Solution:
Tc is the highest Temp where a gas can exist in liquid state. Above this no liquid state exist hence it is not possible to liquify the gas no matter what pressure is applied.
Q4. A catalyst increases the rate of the chemical reaction for the conversion of reactants to products by
Answer : Option C
Explaination / Solution:
A catalyst increases the rate of the chemical reaction by making available a new low energy pathway for the conversion of reactants to products. It increases the rate of forward and reverse reactions that pass through the same transition state and does not affect equilibrium. Catalyst lowers the activation energy for the forward and reverse reactions by exactly the same amount. Catalyst does not affect the equilibrium composition of a reaction mixture. It does not appear in the balanced chemical equation or in the equilibrium constant expression.
Q5. The bond –CO–NH– is called
Answer : Option B
Explaination / Solution:
Peptide linkage is present in proteins formed by combination of amino acids.
Q6. One of the following alcohols do not undergo oxidation reaction
Answer : Option A
Explaination / Solution:
The outcome of oxidation reactions of alcohols depends on the substituents on the carbinol carbon. In order for each oxidation step to occur, there must be H on the carbinol carbon.
- Primary alcohols can be oxidised to aldehydes or further to carboxylic acids. In aqueous media, the carboxylic acid is usually the major product. PCC or PDC, which are used in dichloromethane, allow the oxidation to be stopped at the intermediate aldehyde.
- Secondary alcohols can be oxidised to ketones but no further:
- Tertiary alcohols cannot be oxidised (no carbinol C-H)
Q7. The unusual behavior of benzene is explained by
Answer : Option D
Explaination / Solution:
resonance stabilisation explains the unusual stability of benzene.There is pi electron delocalisation in the ring which enhances the stability of the molecule.
Q8. If the temperature of an aqueous solution increases, it will cause
Answer : Option D
Explaination / Solution:
As temperature increases volume also increases and so Molarity decrease.
Q9. Diazonium salts are used in the preparation of
Answer : Option A
Explaination / Solution:
Diazonium salt on reaction with other aromatic compounds produces dyes.
Q10. In oxygen difluoride and dioxygen difluoride, the oxygen is assigned an oxidation number of
Answer : Option A
Explaination / Solution:
Oxidation state of O in OF2 is +2 and O2F2 is +1. Because the number assigned to oxygen will depend upon the bonding state of oxygen.
