Organic Tests

Question 1

test for carboxylic acids

Answer 1

1. add 2cm^3 test solution to test tube
2. 1 spatula of solid NaCO3 or 2cm^3 NaCO3 solution
3. if solution effervesces/fizzes, bubble gas produced through some lime water in another test tube
4. if limewater goes cloudy CO2 has been produced and its a +ve result for carboxylic acid

Question 2

test for alkenes / unsaturation

Answer 2

1. add 2cm^3 of test solution to test tube
2. add 2cm^3 bromine water to test tube
3. shake test tube
4. if it goes from orange to colourless then its a +ve result for alkene

Question 3

fehlings solution test

Answer 3

1. add 2cm^3 fehlings (clear blue solution) to test tube
2. add 5 drops of test solution
3. put test tube in hot water bath + heat gently
4. blue —> brick red = aldehyde
   blue —> stay blue = ketone

Question 4

fehlings equation full

Answer 4

2Cu^2+(aq) + 2OH-(aq) + 2e- —> Cu2O(s) + H2O(l)

Question 5

fehlings half equation

Answer 5

Cu^2+ + e- —> Cu^+

Question 6

making tollens reagent

Answer 6

1. 2cm^3 of 0.1 moldm^-3 silver nitrate solution in test tube
2. add few drops dilute NaOH solution