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Chemistry

A Level

Why does hydrogen bonding occur in water?

Hydrogen bonding results from the great difference in electronegativity between oxygen and hydrogen. Electronegativity is the ability of an atom to pull electrons towards itself in a covalent bond. As oxy...

Answered by Myles O. • Chemistry tutor

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What are the redox reactions involving carbonyls?

Carbonyls are aldehydes and ketones, both can be a product of an alcohol's oxidation reaction. A common reagent for that is potassium dichromate and sulphuric acid (the dichromate ion is reduced to a Cr

Answered by Krisztina J. • Chemistry tutor

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What product would you expect to obtain when reacting ethanal (or acetaldehyde) with potassium cyanide (KCN) in dilute acid? Draw a curly arrow mechanism for this transformation, and determine whether you obtain one enantiomer or a racemic mixture.

The product obtained is a cyanohydrin, with the formula CH3CH(OH)(CN) where the cyanide anion has acted as a nucleophile towards the aldehyde. The mechanism would first show the lone pair on the carbonyl ...

Answered by Alex S. • Chemistry tutor

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Elements in the Periodic Table often show periodic trends. Describe and explain the periodic trend in atomic radius and electronegativity from Na to Cl.

Atomic Radius - As you go across the Periodic Table from left to right, the atomic radius decreases. This is because the electrons are added to the same shell and as you move from left to right. At the sa...

Answered by Lauren M. • Chemistry tutor

2200 Views

Define the term 'first ionisation energy' and explain why the first ionisation energy shows a general increase across period 2

The first ionisation energy is the energy required to remove an electron from each atom in one mole of gaseous atoms to produce +1 charged gaseous ions.The first ionisation energy shows an general increas...

Answered by Naledi N. • Chemistry tutor

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