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Assertion (A): Trans [CrCl2(ox)2]3− shows optical isomerism.
Reason (R): Optical isomerism is common in octahedral complexes involving didentate ligands.
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For the pair phenol and cyclohexanol, answer the following:
Why is phenol more acidic than cyclohexanol?
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Complete the reaction with the main product formed:
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Convert bromoethane to propanamine.
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Give the mechanism of the following reaction:
\[\ce{CH3CH2OH ->[H2SO4][413 K] CH3CH2-O-CH2CH3 + H2O}\]
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The following questions are case-based questions. Read the passage carefully and answer the questions that follow:
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Nucleophilic Substitution: Influences of solvent polarity: The reaction rate (SN2) of 2-bromopropane and NaOH in ethanol containing 40% water is twice slower than in absolute ethanol. Hence the level of solvent polarity has an influence on both SN1 and SN2 reactions but with different results. Generally speaking, a weak polar solvent is favourable for SN2 reaction, while a strong polar solvent is favourable for SN1. Generally speaking, the substitution reaction of tertiary haloalkane is based on SN1 mechanism in solvents with a strong polarity (for example ethanol containing water). |
Answer the following questions:
(a) Why racemisation occurs in SN1? (1)
(b) Why is ethanol less polar than water? (1)
(c) Which one of, the following in each pair is more reactive towards SN2 reaction? (2)
(i) CH3 – CH2 – I or CH3CH2 – Cl
(ii)
OR
(c) Arrange the following in the increasing order of their reactivity towards SN1 reactions: (2)
(i) 2-Bromo-2-methylbutane, 1-Bromo-pentane, 2-Bromo-pentane
(ii) 1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-Bromo-3- methylbutane
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Why is the boiling point of aldehydes and ketones lower than that of corresponding carboxylic acids?
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Give a chemical test to distinguish between ethanal acid and ethanoic acid.
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An organic compound A with the molecular formula (+) C4H9Br undergoes hydrolysis to form (+) C4H9OH. Give the structure of A and write the mechanism of the reaction.
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Indicate the types of isomerism exhibited by the following complexes and draw the structures for these isomers:
[Pt(NH3)(H2O)Cl2 ]
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Acetic anhydride from acetic acid
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Indicate the types of isomerism exhibited by the following complexes and draw the structure for isomers:
\[\ce{[Pt(NH3)(H2O)Cl2]}\]
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Indicate the types of isomerism exhibited by the following complexes and draw the structures for these isomers: [Pt(NH3)(H2O)Cl2]
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Indicate the type of isomerism exhibited by the following complex and draw the structure for this isomer:
[Pt(NH3)(H2O)Cl2]
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Explain why Grignard reagents should be prepared under anhydrous conditions.
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Indicate the type of isomerism exhibited by the following complex and draw the structure for this isomer: \[\ce{[Pt(NH3)(H2O)Cl2]}\]
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Indicate the types of isomerism exhibited by the following complex and draw the structure for these isomer: \[\ce{[Pt(NH3)(H2O)Cl2]}\]
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Indicate the types of isomerism exhibited by the following complexes and draw the structure for these isomer:
\[\ce{[Pt(NH3)(H2O)Cl2]}\]
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Indicate the types of isomerism exhibited by the following complex and draw the structure for this isomer:
\[\ce{[Pt(NH3)(H2O)Cl2]}\]
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Indicate the types of isomerism exhibited by the following complex and draw the structure for this isomer:
\[\ce{[Pt(NH3)(H2O)Cl2]}\]
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