Eduqas A-Level Chemistry A410QS
Formulae and Equations
Basic Ideas About Atoms
Chemical Calculations
Bonding
Solid Structures
The Periodic Table
Simple Equilibria and Acid-Base Reactions
Thermochemistry
Rates of Reaction
The Wider Impact of Chemistry
Organic Compounds
Hydrocarbons
Halogenoalkanes
Alcohols and Carboxylic Acids
Instrumental Analysis
Redox and Standard Electrode Potential
Redox Reactions
Chemistry of the P-Block
Chemistry of the D-Block Transition Metals
Chemical Kinetics
Enthalpy Changes for Solids and Solutions
Entropy and Feasibility of Reactions
Equilibrium Constants
Acid-Base Equilibria
Stereoisomerism
Aromaticity
Alcohols and Phenols
Aldehydes and Ketones
Carboxylic Acids and Their Derivatives
Amines
Amino Acids, Peptides and Proteins
Organic Synthesis and Analysis
Specified Practical Work
Practical Skills and Techniques
Mathematical Skills in Chemistry
Aldehydes and Ketones
Nucleophilic addition of HCN to aldehydes and ketones
- 3 things to know
- Component 2
Overview
Recall questions on the product and its name, the mechanism named and described with each curly arrow, the attacking species and where it attacks, why a racemic mixture results, why the product from methanal or propanone is not chiral, and the hazards of the reagent.
What you need to know
Answer each one before you reveal it.
Explain why the addition of HCN to a carbonyl compound proceeds fastest at a pH of about 9 to 10
At what temperature is the addition of hydrogen cyanide to a carbonyl compound carried out?
Questions from this subtopic
Each one with the model answer underneath.
- 1
How is the hydrogen cyanide for this reaction usually supplied in the laboratory?
Model answer
It is generated in the flask by adding dilute sulfuric acid to potassium cyanide or sodium cyanide, so the highly toxic gas is never handled as such.
- 2
At what temperature is the addition of hydrogen cyanide to a carbonyl compound carried out?
Model answer
The mixture is held at about 10 to 20 °C.
- 3
Name the nucleophile that attacks the carbonyl compound in this reaction.
Model answer
The cyanide ion, CN⁻.
- 4
Give the equation for the reaction of ethanal with hydrogen cyanide and name the product.
Model answer
CH₃CHO + HCN → CH₃CH(OH)CN, and the product is 2-hydroxypropanenitrile.
- 5
Name and give the formula of the product formed when propanone reacts with hydrogen cyanide.
Model answer
2-hydroxy-2-methylpropanenitrile, (CH₃)₂C(OH)CN.
- 6
Name the mechanism of this reaction and state where the attack takes place.
Model answer
It is nucleophilic addition, and the attack takes place at the δ+ carbon atom of the carbonyl group.
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