pag 6 test for alcohol,aldehyde,alkene carboxylic acid

What’s the test for alkene

1cm³ of bromine water to 2 drops of alkene + shake vigorously

Orange - colourless

What’s the reagent conditions and reaction and observation in tollens reaction for aldeheys

Reagent - tollens reagent ( mixing aqueous ammonia and silver nitrate to form [ag(NH3)2]

Conditions - heat gently

Reaction - only aldehydes oxidised by t.r forms carboxylic acid + silver ions are reduced to silver atoms

Observation - silver mirror

What’s thee equation for ethanal reacting with tollens reagent and forming silver atoms and the other products

CH3CHO + 2AG+. + H20. = CH3COOH + 2AG + 2H+

What is th method of using tollens reagent

1cm³ of silver nitrate and add one drop of NAOH solution to form precipitate of silver oxide — add ammonia solution until colourless solution is formed —- add drops of unknown + leave in water bath

What is the reagent, conditions, reaction,observation for using Fehlings solution

Reagent - Fehlings solution containing cu2+ ions

Conditions - heat gently

Reaction - only aldehyde oxidised to form carboxylic acid and copper(2) ions are reduced to copper oxide

What’s the equation of Fehlings solution being used on ethanal

CH3CH0 + 2CU2+. + 2H2O. === CH3COOH + CU2O +4H+

What’s the test for carboxylic acid and what’s the equation

Add a small amount of sodium carbonate solid to 0.5cm³ of unknown solution

Carboxylic acids fizz due to co3 produced

2CH3CO2H. + NA2CO3 ———- 2CH3CO2-NA+. +. H2O + CO2

How to test for halogen aljakanes

Add 5 drops to Halogenalkanes to 1cm³ of naoh

Warm contents in a beaker with hot water

Acidify contents by adding 2cm³ of dilute nitric acid and then add 1cm³ of silver nitrate

Should form silver halides

Why is naoh used in testing for Halogenalkanes

The oh- ions replace the br by nucleophilliic substitution

What is the silver nitrate used for?

The nitric acid removes carbonate and hydroxide impurities to form precipitate

What are the 2 equations for testing for halogen alkanes

Why does the iodoalkanes form a ppt with the silver nitrate first

The c-i bond is weakest and so it hydrolyses the quickest in comparison to water which is a poor nucleophile and reacts slowly withhaloalkanes in a substitution reaction

What dos it mean if the ppt in halogenalkenes test is formed quickly

The quicker the ppt is formed the faster the substitution reaction and the more reactive the haloalkane

The AGI is quickest

Then AGBR

THEN AGCl (slowest ppt to form)

How do u test for metals

Metallic sodium to alcohol to form hydrogen gas to then do squeaky pop test

How do u test for alcohols

Acified potassium dichromate

The primary and secondary alcohols ar reduced to turn orange dischromate to green chromate (III) ions