CBSE 12TH CHEMISTRY - Online Test
Q1. Drugs which mimic the natural messenger by switching on the receptor are called
Answer : Option C
Explaination / Solution:
Agonists are drugs which mimic the natural messenger by switching on receptors.
Q2. What is the coordination number of chromium in [Cr(NH3)2(H2O2)2]Cl3?
Answer : Option D
Explaination / Solution:
There are 4 ligands attachted so CN= 4.
Q3. When measuring conductivity with a conductivity cell, cell constant denoted by the symbol G* is given by (electrode area of cross section equal to ‘A’ and separated by distance ‘l’)
Answer : Option C
Explaination / Solution:
Cell constant = length of electrodes/ Area of electrodes.
Q4. In the following reaction, the compound used in the reaction for synthesizing ethyl fluoride is – +AgF → H3C – F + AgBr
Answer : Option C
Explaination / Solution:
Alkyl fluorides is only formed by Swartz reaction.in swartz reaction alkyl chlorides or bromide reacts with metallic flouride agf hg2f2 to form alkyl flourides.
Q5. The effect of temperature on reaction rate is given by
Answer : Option C
Explaination / Solution:
k =A exp(-kt)
Q6. Decomposition of H2O2 can be prevented in the presence of
Answer : Option D
Explaination / Solution:
Glycerol prevents the decomposition of H2O2
Q7. Glucose does not give Schiff’s test because of the formation of cyclic
Answer : Option A
Explaination / Solution:
Schiffs test is given by aldehydes, as aldehydic group is not free here.
Q8. Aldehydes are reduced to the corresponding alcohols by addition of hydrogen in the presence of catalysts to form
Answer : Option C
Explaination / Solution:
- Aldehydes and ketones are most readily reduced with hydride reagents.
- The reducing agents LiAlH4 and NaBH4 act as a source of 4 x H- (hydride ion)
- Overall 2 H atoms are added across the C=O to give H-C-O-H
- Hydride reacts with the carbonyl group, C=O, in aldehydes or ketones to give alcohols.
- The substituents on the carbonyl dictate the nature of the product alcohol.
- Reduction of methanal (formaldehyde) gives methanol.
- Reduction of other aldehydes gives primary alcohols.
- Reduction of ketones gives secondary alcohols.
Q9. p – toluenesulphonyl chloride does not react with
Answer : Option C
Explaination / Solution:
does not react with all these amines
Q10. At constant temperature the osmotic pressure of a solution is
Answer : Option B
Explaination / Solution:
Л=cRT
