Which carboxylate ion among the following is the most stable?
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Electrophilic addition reactions proceed in two steps. The first step involves the addition of an electrophile. The major intermediate formed in the first step is:
\(\mathrm{H}_3 \mathrm{C}-\mathrm{HC}=\mathrm{CH}_2+\mathrm{H}^{+} \rightarrow \text { ? }\)
1. carbanion
2. carbocation
3. carbocation
4. carbanion
The correct representation involving heterolytic fission of among the following is:
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The addition of HCl to an alkene proceeds in two steps. The first step is the attack of H+ ion on the double bond portion. The same can be shown as-
1. | 2. | ||
3. | 4. | All of these are possible |
Match the type of mixture of compounds in Column-I with the technique of separation/purification given in Column-II.
Column-I | Column-II | ||
A. | Two solids which have different solubilities in a solvent and which do not undergo a reaction when dissolved in it | 1. | Steam distillation |
B. | Liquid that decomposes at its boiling point | 2. | Fractional distillation |
C. | Steam volatile liquid | 3. | Crystallisation |
D. | Two liquids that have boiling points close to each other | 4. | Distillation under reduced pressure |
Codes:
A | B | C | D | |
1. | 3 | 4 | 1 | 2 |
2. | 1 | 2 | 3 | 4 |
3. | 1 | 4 | 3 | 2 |
4. | 4 | 1 | 3 | 2 |
Match Column I with Column II.
Column I | Column II | ||
A. | Dumas method | 1. | AgNO3 |
B. | Kjeldahl’s method | 2. | Silica gel |
C. | Carius method | 3. | Nitrogen gel |
D. | Chromatography | 4. | Ammonium sulphate |
Choose the correct answer from the options given below:
A | B | C | D | |
1. | 3 | 4 | 1 | 2 |
2. | 1 | 2 | 3 | 4 |
3. | 1 | 4 | 3 | 2 |
4. | 4 | 1 | 3 | 2 |
Which of the following carbon marked with asterisk is expected to have greatest positive charge?
1. | 2. | ||
3. | 4. |
The correct order of decreasing stability of the following carbocations is:
I | \( \begin{aligned} &~~~~~~~~~~~~\oplus\\ & CH_3 - CH-CH_3 \end{aligned}\) |
II | \( \begin{aligned} &~~~~~~~~~~~~\oplus\\ & CH_3 - CH-OCH_3\end{aligned}\) |
III | \( \begin{aligned} & ~~~~~~~~~~~~\oplus\\ &CH_3 - CH-CH_2- OCH_3\end{aligned}\) |
1. | II > I > III | 2. | I > II > III |
3. | II < I < III | 4. | I < II < III |
Paper chromatography operates based on which of the following principles?
1. Adsorption
2. Partition
3. Solubility
4. Volatility