All Tests You Need To Know
Name Method Positive Outcome Risk As-
sessment
Benedict’s solution + Fehling’s solution Aldehyde = blue solution will Fehling’s solution =
Aldehyde + Ketone 1. Add 2 cm Fehling’s or Benedict’s solution give a red precipitate corrosive
3
to a test tube (it should be blue) Ketone = nothing Benedict’s solution =
2. Add 5 drops of the aldehyde or ketone irritant
3. Put the test tube in a hot water bath
Tollens’ Reagent
1. Put 2 cm3 of 0.10 mol dm−3 silver nitrate so- Aldehyde = silver mirror Tollens’ reagent =
lution in a test tube Ketone = Nothing explosive + an irri-
2. Add a few drops of dilute sodium hydroxide tant
solution (light brown precipitate should Sodium hydroxide =
form) corrosive + harmful
3. Add drops of dilute ammonia solution until
the brown precipitate dissolves completely
4. Place the test tube in a hot water bath
5. Add 10 drops of the aldehyde/ketone
6. Wait for a few minutes
1. Add 2 cm3 of the solution you want to test to Carboxylic acid = solution will Sodium carbonate +
Carboxylic Acid a test tube fizz. Limewater will turn cloudy limewater are irri-
2. Add 1 small spatula of solid sodium carbon- tants
ate (or 2 cm3 of sodium carbonate solution) Not carboxylic acid = nothing
3. If the solution begins to fizz, bubble the gas happens
produced through some limewater in a sec-
ond test tube
Name Method Positive Outcome Risk As-
sessment
Benedict’s solution + Fehling’s solution Aldehyde = blue solution will Fehling’s solution =
Aldehyde + Ketone 1. Add 2 cm Fehling’s or Benedict’s solution give a red precipitate corrosive
3
to a test tube (it should be blue) Ketone = nothing Benedict’s solution =
2. Add 5 drops of the aldehyde or ketone irritant
3. Put the test tube in a hot water bath
Tollens’ Reagent
1. Put 2 cm3 of 0.10 mol dm−3 silver nitrate so- Aldehyde = silver mirror Tollens’ reagent =
lution in a test tube Ketone = Nothing explosive + an irri-
2. Add a few drops of dilute sodium hydroxide tant
solution (light brown precipitate should Sodium hydroxide =
form) corrosive + harmful
3. Add drops of dilute ammonia solution until
the brown precipitate dissolves completely
4. Place the test tube in a hot water bath
5. Add 10 drops of the aldehyde/ketone
6. Wait for a few minutes
1. Add 2 cm3 of the solution you want to test to Carboxylic acid = solution will Sodium carbonate +
Carboxylic Acid a test tube fizz. Limewater will turn cloudy limewater are irri-
2. Add 1 small spatula of solid sodium carbon- tants
ate (or 2 cm3 of sodium carbonate solution) Not carboxylic acid = nothing
3. If the solution begins to fizz, bubble the gas happens
produced through some limewater in a sec-
ond test tube
