Exercise 04: Formaldehyde

Question 1

Three (3) General Aldehyde Reactions

Answer 1

1. Silver Nitrate Test
2. Fehling’s Test
3. Nessler’s Test

Question 2

1. Place 1 mL of sample in a test tube.
2. Add a _____ of silver nitrate to the solution to be tested.
3. Heat the solution to boiling.
4. Observe the results.

Answer 2

Silver Nitrate Test
2. Few Drops

Question 3

1. Place 1 mL of sample in a test tube.
2. Heat the sample solution with _____ of Fehling’s reagent.
3. Observe for the formation of color.

Answer 3

Fehling’s Test
2. 5 drops

Question 4

1. Place 1 mL of sample in a test tube.
2. Add _____ of Nessler’s reagent to 1 mL of the solution.
3. Heat the solution to boiling.
4. Observe the results.

Answer 4

Nessler’s Test
2. 5 drops

Question 5

Hehner’s Test as modified by _____.

Answer 5

Leonard

Question 6

1. Place _____ of sample in a test tube.
2. Mix with _____ of fresh unboiled milk and _____ of 25% HCI containing a few drops of ferric chloride test solution.
3. Boil gently for a minute.
4. Observe the results.

Answer 6

Hehner’s Test
1. 5 mL
2. 2 mL; 7 mL

Question 7

1. Place 1 mL of sample in a test tube.
2. Treat the sample solution with _____ and evaporate slowly.
3. Observe the results.

Answer 7

Hexamethylene Tetra-Amine Test
2. Ammonia

Question 8

1. Place 1 mL of sample in a test tube.
2. To the sample solution add an equal quantity of _____.
3. Sprinkle a pinch of phloroglucinol in the surface of the solution.
4. Observe the results.

Answer 8

Phloroglucinol Test
2. 15% HCI

Question 9

1. Place 1 mL of sample in a test tube.
2. To the sample solution add a mixture of an equal volume of _____ and _____.
3. Heat to boiling.
4. Observe the results.

Answer 9

Resorcinol Test
2. 5% Resorcinol; 40% Sodium Hydroxide Solution

Question 10

1. Place 1 mL of sample in a test tube.
2. To the sample solution add 10 drops of _____ solution and then 2 drops of _____ and then finally add 10 drops of _____.
3. Observe the results.

Answer 10

Rimini’s Phenyl Hydrazine Test
2. 0.5% Phenyl-Hydrazine Hydrochloride; 5% Sodium Nitroprusside; and 10% Sodium Hydroxide