Synthetic Dyes

Q. Toluene reacts with chromyl chloride in presesnce of $C{S}_2$ followed by hydrolysis give which of the following compound?

1. Benzaldehyde
2. Benzoyl chloride
3. Benzene
4. $o-$chlorotoluene

Q.

Why is pH 10 buffer used in EDTA titration?

Q. Which of the following will be formed when phenol reacts with concentrated nitric acid?

1. $2-$Nitrophenol
2. $2,6-$Dinitrophenol
3. $4-$Nitrophenol
4. $2,4,6-$Trinitrophenol

Q.

^{Sulphurous acid (H₂SO₃) has K_a1 = 1.7 × 10–2 and K_a2 = 6.4 × 10–8. The pH of 0.588 M H₂SO₃ is _________. (Round off to the nearest integer).}

Q. Diazomethane reacts with acid chlorides followed by Ag2O and hydrolysis to produce 1) carboxylic acid 2) alcohol 3) amine 4) imines

Q. What is the name for orange azo dye which is formed by the reaction between benzene diazonium chloride and phenol?

1. p-Hydroxyazobenzene
2. $\beta$-Naphthylazobenzene
3. p-Aminoazobenzene
4. p-N, N-Dimethylaminoazobenzene

Q. Benzyl chloride $\left(C_6{H}_{5}C{H}_{2}Cl\right)$ can be prepared from toluene by chlorination with

1. $S{O}_{2}C{l}_2$
2. $SOC{l}_2$
3. $C{l}_2$
4. $NaOCl$

Q. when ethene reacts with bromine in aqueous solution of sodium chloride.the products obtained are

Q.

p-amino azo benzene is obtained by treating diazoniumchloride with:

1. Aniline

2. Phenol

3. Alcohol

4. Benzoic acid

Q. why in reimer tiemann reaction major product is ortho product?

Q.

Under what reaction conditions $\left(\text{acidic/basic}\right),$ the coupling reaction of aryldiazonium chloride with aniline is carried out?

Q. Aniline in a set of the following reactions yielded a coloured product Y.
The structure of 'Y' would be :

1. 
2. 
3. 
4. 

Q. Aniline when diazotized in cold and then treated with dimethyl aniline gives a coloured product. Its structure would be.

1. 
2. 
3. 
4. 

Q.

The correct order of nucleophilic-addition elimination reaction is

1. Amide > Ester > Acid anhydride > Acyl chloride

2. Ester > Acid anhydride > Amide > Acyl chloride

3. Acid anhydride > Acyl chloride > Ester > Amide

4. Acyl chloride > Acid anhydride > Ester > Amide

Q.

Benzenediazonium chloride when treated with phenols gives azo dyes, to get best result the pH of the medium should be

1. Around 4

2. Around 10

3. 12

4. Around 8

Q.

Why is fused calcium chloride or concentrated sulphuric acid is used in a desiccator?

Q.

Diazo coupling is useful to prepare________________.

Q.

Chorobenzene is prepared commercially by

1. Raschig process

2. Dow's process

3. Deacon process

4. Etard's process

Q. The formation of phenol from benzene diazonium chloride is a_____.

1. Hydrolysis reaction
2. Pyrolysis reaction
3. Photosynthesis reaction
4. Combustion reaction

Q. Product (B) of the given reaction is ?

1. 
2. 
3. 
4. 

Q. When phenol is distilled with Zn-dust, it gives:

1. benzaldehyde
2. benzoid acid
3. toluene
4. benzene

Q. The number of $\sigma$ and $\pi$ bonds present in Inorganic benzene

1. 
2. 
3. 
4. 

Q. Which of the following is the A in the given reaction

1. Benzene diazonium chloride
2. Benzene
3. Nitrobenzene
4. Aniline

Q. For diazonium ions, the order of reactivity towards diazonium coupling with phenol in the presence of dil. NaOH is

1. III < IV < II < I
2. I < II < IV < III
3. IV < II < I < III
4. I < IV < II < III

Q. Identify the major products $P,Q$ and $R$ in the following sequence of reactions:

1. 
2. 
3. 
4. 

Q. The total number of $\sigma$ and $\pi$ bonds present in azobenzene are:

1. $24\sigma$, $6\pi$
2. $25\sigma$, $7\pi$
3. $27\sigma$, $6\pi$
4. $28\sigma$, $6\pi$

Q. WHAT IS HYBRIDISATION STATE OF BENZYL CARBONIUM ION STEP BY STEP IN EASY FORM

Q. The colour of dye formed in the reaction between benzene diazonium chloride and phenol is:

1. yellow
2. orange
3. purple
4. blue

Q.

Aniline when diazotized in cold and then treated with dimethyl aniline gives a coloured product. Its structure would be

[CBSE PMT 2004]

1. 
   

2. 
   

3. 
   

4. 
   

Q. ethyl iodide and n propyl iodide are allowed to undergo wurtz reaction the alkane which will not be obtained in this reaction is