The latest technique for isolation, purification and separation of organic compounds is -
1. | Crystallisation | 2. | Distillation |
3. | Sublimation | 4. | Chromatography |
Nitric acid is added to sodium extract before adding silver nitrate for testing halogens because:
1. Nitric acid reduces sulphide
2. Nitric acid decomposes NaCN and Na2S
3. Nitric acid oxidises the organic compound
4. Nitric acid acts as a dehydrating agent
Metallic sodium is fused with organic compounds for testing nitrogen, sulphur, and halogens. The correct reason behind this is:
1. | To convert all compounds to their ionic form. |
2. | Sodium reduces the compounds. |
3. | Sodium converts all compounds in their covalent form. |
4. | None of the above. |
The most stable carbocation among the following is-
1. \(({CH_3})_3C\overset{+}{C}H_2\)
2. \(({CH_3})_3\overset{+}{C}\)
3. \({CH_3}CH_2\overset{+}{C}H_2\)
4. \(({CH_3})\overset{+}{C}HCH_2CH_3\)
is more stable than because :
1. | NO2 shows +I effect |
2. | NO2 shows -I effect |
3. | NO2 decreases the positive charge on the compound |
4. | Ethyl group increases positive charge on the compound |
An electrophile among the following is :
1. | \(\mathrm{OH}^-\) | 2. | \(\mathrm{NC}^-\) |
3. | \(R_3C^-\) | 4. | Carbonyl group |
0.284 g of an organic substance gave 0.287 g AgCl in a carius method for the estimation of halogen. The percentage of Cl in the compound is-
1. 5%
2. 18%
3. 25%
4. 33%
Which carboxylate ion among the following is the most stable?
1. | 2. | ||
3. | 4. |
The correct representation involving heterolytic fission of among the following is:
1. | |
2. | |
3. | |
4. |