Test Tube Reactions

Question 1

Alkenes test and result

Answer 1

Shake with bromine water
Bromine water turns from orange to clear and colourless if alkene is present

Question 2

Primary or secondary alcohol test and result

Answer 2

Test
Add acidified K2Cr2O7
Warm

Result
Solution will turn orange to green

Question 3

Aldehyde

Answer 3

Test
Warm with Fehling’s solution or Warm with Tollen’s solution

Result
Blue solution turns to a brick red precipitate
Silver mirror forms if aldehyde present

Question 4

Carboxylic acid test and result

Answer 4

Test
Add Na2CO3 (either solution or solid)

Result
Effervescence

Question 5

Testing for H2 gas

Answer 5

Test
Apply lit splint

Result
Squeaky pop occurs

Question 6

CO2 Gas

Answer 6

Test
Bubble through lime water

Result
Solution turns cloudy

Question 7

O2 gas

Answer 7

Test
Apply glowing splint

Result
The splint will re-light

Question 8

SO4^-2 test

Answer 8

Test
Add BaCl2 solution

Result
A white precipitate will form

Question 9

Halide ions test

Answer 9

Test
Add HNO3 then AgNO3

Result
White ppt = Cl- ions will dissolve in dilute ammonia
Cream ppt = Br- ions will only dissolve in concentrated ammonia
Yellow ppt = I- ions is insoluble in ammonia

Question 10

CO3^-2 ions test

Answer 10

Test
Add Any Acid

Result
Effervescence as CO2 is given off