CBSE 12TH CHEMISTRY - Online Test
Q1. The compound which forms acetaldehyde when heated with dilute NaOH is
Answer : Option D
Explaination / Solution:
Q2.
For the reduction of silver ions with copper metal the standard cell potential was found to be +0.46V at 25°C. The value of standard Gibbs energy, ΔG° wll be (F = 96500 C )
Answer : Option A
Explaination / Solution:
Q3. A dibromo derivative of an alkane reacts with sodium metal to form an alicyclic hydrocarbon. The derivative is
Answer : Option D
Explaination / Solution:
This is intramolecular wurtz reaction.
Q4. The substance that slows down the reaction without being consumed is known as
Answer : Option B
Explaination / Solution:
Inhibitors inhibits the action of catalyst and hence slows down the rate of reaction.
Q5. A biochemical catalyst is
Answer : Option C
Explaination / Solution:
Enzymes are biological catalyst, they catalize different chemical reactions in body.
Q6. The carrier of hereditary character is.
Answer : Option D
Explaination / Solution:
Nucleotides is carrier of hereditary
Q7. Building unit of protein is.
Answer : Option A
Explaination / Solution:
Protein is built by α – Aminoacid
Q8. Which of the following is most acidic?
Answer : Option C
Explaination / Solution:
In cases of halogen derivatives of phenols or aniline or benzoic acid etc, it is very helpful to understand that all halogens when attached to benzene ring exerts -I as well as +R effect.
In case of Cl, Br and I, the +R effect has almost no effect on reactivity, acidic character or basic character of benzene ring. It is due to very less effective overlapping involving 2p of carbon and 3p or 4p or 5p of halogen.
Hence, only -I effect becomes the deciding factor, which is most dominant from ortho-position and least effective from para-position. So m chlorophenol is most acidic.
Q9.
Calculate the molarity of liquid HCl solution whose density is 1.17 g/cm3
.
Answer : Option C
Explaination / Solution:
M= (1.17 x 1000)(36.5)
Q10. Anisole reacts with a mixture of concentrated sulphuric and nitric acids to yield a mixture of ortho and para nitroanisole
Answer : Option C
Explaination / Solution:
Para isomer is major because ethere is no steric hinderance and also at para +M effect will work effectively.
