CBSE 12TH CHEMISTRY - Online Test
Q1. Choose the most appropriate among the following for Bakelite
Answer : Option A
Explaination / Solution:
Bakelite undergoes extensive cross linking.
Q2. At what temperature white phosphorous changes to red phosphorous?
Answer : Option D
Explaination / Solution:
White phosphorus when heated to 573 K in an inert atmosphere for several days red Phosphorus is obtained.
Q3. The diagram shows schematic representation of
Answer : Option D
Explaination / Solution:
This is hydraulic washing or gravity separation. Here whwn stream of water is passed it takes away all the impurity with it.
Q4. Maximum oxidation state is shown by
Answer : Option D
Explaination / Solution:
Os shows maximum oxidation state of +8.
Q5. Aldehydes are prepared by reducing nitriles to corresponding imines with stannous chloride in the presence of hydrochloric acid. This reaction is called
Answer : Option D
Explaination / Solution:
Reaction for preparation of aldehydes by reducing RCN is stephens Reaction.
Q6. Zantac, Cimetidine, Ranitidine are all
Answer : Option C
Explaination / Solution:
They all are antihistamines.
Q7. Which of the following is non – ionizable?
Answer : Option A
Explaination / Solution:
In A there is no ion present outside the coordination sphere so it is ionizable.
Q8. Conductivity always decreases with decrease in concentration both, for weak and strong electrolytes because of the fact that
Answer : Option C
Explaination / Solution:
Conductivity of solution decreases with dilution because number of ions per unit volume decreases.
Q9. Which compound in the following pair reacts faster in SN2 reaction with OH– ?
i) CH3Br or CH3
ii) CH3Cl, (CH3)3CCl
i) CH3Br or CH3
ii) CH3Cl, (CH3)3CCl
Answer : Option A
Explaination / Solution:
For SN2 reaction leaving group should be good and alkyl halide should be primary.so CH3Br and CH3Cl are 10organic compounds hence rate of sn2 reaction will be more.
Q10. The chemical reaction in which reactants require high amount of activation energy are generally
Answer : Option A
Explaination / Solution:
If activation energy is high rate of reaction will decrease and reaction will be slow.
