CBSE 12TH CHEMISTRY - Online Test
Q1.
The compounds above are very good antioxidants. They are
The compounds above are very good antioxidants. They are
Answer : Option C
Explaination / Solution:
They are BHT and BHA.
Q2. The oxidation state of Ag in tollen’s reagent is
Answer : Option A
Explaination / Solution:
oxidation state of Ag in tollen’s reagent is +1.
Q3. In the primary batteries
Answer : Option C
Explaination / Solution:
Primary batteries cannot be recharged and reused.
Q4. A mixture containing two enantiomers in equal proportions
Answer : Option D
Explaination / Solution:
For a mixture of two enantiomers , one rotates the plane polarized light towards left and other towards right therefore there is no optical rotation and hence mixture is optically inactive.
Q5. The constant k used in rate equation is known as
Answer : Option B
Explaination / Solution:
Rate constant is also known as velocity constant.
Q6. The basic principle of Cottrell precipitator is
Answer : Option D
Explaination / Solution:
It is used for decreasing air pollution by neutralizing the colloid.
Q7. Amino acids are components of
Answer : Option D
Explaination / Solution:
Proteins are formed by combination of amino acids
Q8. Boiling points of alcohols and phenols are higher than
Answer : Option B
Explaination / Solution:
- The oxygen atom of an alcohol is sp3 hybridised and has two non bonding pairs of electrons.
- The O-H bond of alcohols is strongly polarised and hydrogen bonding occurs in much the same way as in water molecules
- As a consequence, alcohols have relatively high boiling points compared to other organic compounds of a similar molecular weight.
Q9. Aquatic animals are more comfortable in cold water rather that warm water because
Answer : Option D
Explaination / Solution:
Because of increase in kinetic energy of gas molecules with temperature there tendency to escape from the liquid will increase.
Q10. One of the following behave like Lewis base
Answer : Option C
Explaination / Solution:
Amines behave as lewis base because of presence of lone pair on N, whereas in amides and cyanides the lone pair on nitrogen is involved in resonance. In esters, the lone pair on oxygen is involved in resonance.
