What is the formulae? Hydrochloric acid Sulfuric acid Sodium hydroxide Sodium chloride Sodium sulfate

Starter: what is the formulae? Hydrochloric acid HCl Sulfuric acid H2SO4 Sodium hydroxide NaOH Sodium chloride NaCl Sodium sulfate Na2SO4

A level chemistry

Practical Endorsement

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Name these compounds

Name these compounds Propan-1-ol Propan-2-ol Methane Methanoic Acid Butyl Propanoate

(suffix –one and number in the middle to show location if needed) Propan-1-ol Propan-2-ol These chemicals can be oxidised to... An Aldehyde (suffix –al) A Ketone (suffix –one and number in the middle to show location if needed)

CARBONYL COMPOUNDS - STRUCTURE Structure carbonyl groups consists of a carbon-oxygen double bond the bond is polar due to the difference in electronegativity Difference ALDEHYDES - at least one H attached to the carbonyl group C = O H C = O H CH3

CARBONYL COMPOUNDS - STRUCTURE Structure carbonyl groups consists of a carbon-oxygen double bond the bond is polar due to the difference in electronegativity Difference ALDEHYDES - at least one H attached to the carbonyl group KETONES - two carbons attached to the carbonyl group C = O H C = O H CH3 C = O CH3 C = O C2H5 CH3

CARBONYL COMPOUNDS - FORMULAE Molecular C3H6O Structural C2H5CHO CH3COCH3 Displayed Skeletal C = O H C2H5 C = O CH3 H C C C H H O H H H H C C C O H H H H H O O

CARBONYL COMPOUNDS - NOMENCLATURE Aldehydes C2H5CHO propanal Ketones CH3COCH3 propanone CH3CH2COCH3 butanone CH3COCH2CH2CH3 pentan-2-one CH3CH2COCH2CH3 pentan-3-one C6H5COCH3 phenylethanone

Name these Carbonyls

Name these Carbonyls Pentanal Pentan-2-one Butanone Pentan-3-one

CARBONYL COMPOUNDS - FORMATION ALDEHYDES Oxidation of primary (1°) alcohols RCH2OH + [O] ——> RCHO + H2O beware of further oxidation RCHO + [O] ——> RCOOH Reduction of carboxylic acids RCOOH + [H] ——> RCHO + H2O KETONES secondary (2°) alcohols RCHOHR + [O] ——> RCOR + H2O

Practical Skills Prepare your workstation for safe working. Prepare some Tollens Reagent by placing 1cm3 of Silver Nitrate solution into a test tube. Add one drop of Sodium Hydroxide Solution to the Silver Nitrate solution. Dissolve the precipitate formed by adding Ammonia solution drop-wise until the precipitate JUST dissolves. Divide the solution into 2 by pouring into 2 clean test tubes. Add 10 drops of propanal to one of the tubes and 10 drops of propanone to the other. Label the tubes. Place both tubes into a beaker of boiled water. Leave until no further changes occur (approx 5 min). Record your observations. Put 1cm3 of acidified Potassium Dichromate (VI) solution into a clean test tube and add 10 drops of propanal. Warm Gently Repeat step 7 using propanone instead of propanal and record your observations.

CARBONYL COMPOUNDS - IDENTIFICATION Differentiation to distinguish aldehydes from ketones, use a mild oxidising agent Tollen’s Reagent ammoniacal silver nitrate mild oxidising agent which will oxidise aldehydes but not ketones contains the diammine silver(I) ion - [Ag(NH3)2 ]+ the silver(I) ion is reduced to silver Ag+(aq) + e¯ ——> Ag(s) the test is known as THE SILVER MIRROR TEST

CARBONYL COMPOUNDS - IDENTIFICATION Differentiation to distinguish aldehydes from ketones, use a mild oxidising agent Tollen’s Reagent ammoniacal silver nitrate mild oxidising agent which will oxidise aldehydes but not ketones contains the diammine silver(I) ion - [Ag(NH3)2 ]+ the silver(I) ion is reduced to silver Ag+(aq) + e¯ ——> Ag(s) the test is known as THE SILVER MIRROR TEST Acidified Potassium Dichromate (VI) Another common mild oxidising agent which can oxidise aldehydes and not ketones. Ketones are very resistant to oxidation and can only be oxidised using very strong agents and aggressive conditions. Aldehyde Ketone Green colour observed Remains orange

CARBONYL COMPOUNDS - CHEMICAL PROPERTIES OXIDATION • provides a way of differentiating between aldehydes and ketones • mild oxidising agents are best • aldehydes are easier to oxidise • powerful oxidising agents oxidise ketones to a mixture of carboxylic acids ALDEHYDES easily oxidised to acids RCHO(l) + [O] ——> RCOOH(l) CH3CHO(l) + [O] ——> CH3COOH(l) KETONES oxidised under vigorous conditions to acids with fewer carbons C2H5COCH2CH3(l) + 3 [O] ——> C2H5COOH(l) + CH3COOH(l)

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