3.3.6.1 Test Tube Reactions

What is the test for an alkene

Shake with bromine water

What is a positive result of alkenes test

Orange/brown to colourless colour change

Describe the test for halogenoalkanes

Add aqueous sodium hydroxide and warm gently, acidify with nitric acid, add silver nitrate

Give the formula for nitric acid

HNO3

Give the formula for silver nitrate

AgNO3

What coloured precipitate does halogenoalkanes chlorine form

White

What coloured precipitate does halogenoalkanes bromine form

Cream

What coloured precipitate does halogenoalkanes iodine form

yellow

Describe the general positive result of a halogenoalkanes test

A coloured precipitate forms

Describe the test for an alcohol

Add acidified potassium dichromate solution

Give the formula for potassium dichromate

K2Cr2O7

What is the result for an alcohol test with primary and secondary alcohols

Orange to green colour change

What is the result for an alcohol test with tertiary alcohols

No colour change or reaction

Describe the two test options for aldehydes

Warm with Tollen’s reagent or warm with Fehling’s solution

Describe the result for an aldehyde Tollen’s test

Silver mirror forms

Describe the result for an aldehyde Fehling’s test

Blue solution turns to a red precipitate

Describe the test for carboxylic acids

Add sodium hydrogen carbonate

What is the formula for a chemical used in carboxylic acid tests

NaHCO3

What is a positive result of a carboxylic acid test

CO2 gas is formed