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Chemistry

A Level

Part 1: Calculate the empirical formula for a substance with the following composition: H 6.71%; C 40.00%; O 53.29%

C = 12 g/molO = 16 g/molH = 1 g/mol
Ratio of C = 40/12 = 3.33Ratio of O = 53.29/16 = 3.33Ratio of H = 6.71/ 1 = 6.71Divide largest value by smallest value = 6.71/3.33 = 2Empirical formula = CH2O

Answered by Rachael T. • Chemistry tutor

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Write an equation for the complete combustion of C9H20

Complete combustion is the oxidation of a fuel where the only products exist as CO₂ and H₂O.
C₉H₂₀ + nO₂ ==> nCO₂ + nH_2<...

Answered by Harry F. • Chemistry tutor

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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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