EXP 11: Properties of Aldehydes & Ketones

37-40%

Formalin is ___% solution of formaldehyde in water

(1) Germicide (2) Disinfectant (3) Food Preservant (4) Preserving of Albuminous Tissue; Embalming Agent

4 Uses of Formaldehyde

True

True or false: Formaldehyde is a neutral compound soluble in water.

True

True or false: Acetone is a neutral substance soluble in water.

5

Starting from what number of carbons do ketones become insoluble?

Ethereal Mint Like

Odor of acetone

reducing property

Acetone does not possess ___ ___

Aliphatic

What kind of aldehyde is formalin?

Aromatic

What kind of aldehyde is benzaldehyde?

Cherry

What is the smell of benzaldehyde reminiscent of?

Schiff’s Test

(Part 1) What is the name of this test?

Schiff’s Test

What test is used to check for the presence of aldehydes?

Fuchsin decolorized by sulfur dioxide (SO2) or sulfurous acid (H2SO3)

What is Schiff’s reagant?

Formalin (HCHO), Benzaldehyde (C6H5CHO), Acetone (CH3COCH3)

(Part 1) What are the names and formulas of the substances Schiff’s solution is added to?

Magenta Color

(Part 1) What color does formalin become when Schiff’s solution is added?

Pink Color

(Part 1) What color does benzaldehyde turn when Schiff’s solution is added?

Colorless

(Part 1) What color does acetone turn when Schiff’s solution is added?

Pink Solution

(Part 1) What indicates a positive reaction in the Schiff’s Test?

Resorcinol Test

What is the test specific to formaldehyde?

Formaldehyde (HCHO)

What is the name and formula the Resorcinol Test is specific for?

0.5% Resorcinol Solution (C6H4(OH)2) & Concentrated Sulfuric Acid (H2SO4)

(Part 2) What are the two substances added to formalin?

Colorless liquid and white cloudy precipitate

(Part 2) What is visibly observed as the top layer when resorcinol and sulfuric acid is added to formalin?

Red, flocculent precipitate

(Part 2) What is visibly observed as the junction when resorcinol and sulfuric acid is added to formalin?

Slight yellow-orange

(Part 2) What is visibly observed as the bottom layer when resorcinol and sulfuric acid is added to formalin?

Gelatin

(Part 3) What is the sheet placed in formalin?

The sheet placed in Formalin

(Part 3) Which gelatin sheet did not dissolve when placed in hot water?

Tollen’s, Benedict’s, Fehling’s Solutions

What 3 solutions are mild oxidizing agents of aldehydes?

Silver Mirror/Tollen’s Test

What is the test used to distinguish aldehydes from ketones?

Silver Mirror/Tollen’s Test

(Part 4) What is the name of the test?

Ammoniacal Silver Nitrate (Ag(NH3)2+ & OH-)

(Part 4) What is added in the Silver Mirror/Tollen’s Test?

Formalin & Benzaldehyde

(Part 4) What yielded a positive result in the Silver Mirror/Tollen’s Test?

Acetone (CH3COCH3)

(Part 4) What yielded a negative result in the Silver Mirror/Tollen’s Test?

Silver mirror (Ag)

(Part 4) What is the product of reduction in Tollen’s Test?

Formic/Methanoic Acid (HCOOH)

(Part 4) Aside from silver, what is produced from the reaction between formalin and ammoniacal silver nitrate?

Benzoic Acid (C6H5COOH)

(Part 4) Aside from silver, what is produced from the reaction between benzaldehyde and ammoniacal silver nitrate?

Fehling’s Test

(Part 5) What is the name of the test?

Copper (II) sulfate (CuSO4), sodium hydroxide (NaOH), Rochelle’s salt (sodium potassium tartrate)

(Part 5) What is Fehling’s reagent made of?

Formalin

(Part 5) What is the substance that yielded a positive reaction in the Fehling’s Test?

Aldehydes (excluding Benzaldehyde)

(Part 5) What is the name of the group that yields a positive reaction in Fehling’s Test?

Blue

(Part 5) What color is Fehling’s Solution?

Brick red precipitate

(Part 5) What is the sign of a positive result in the Fehling’s Test?

Brick red cuprous oxide (Cu2O)

(Part 5) What is the color, name, and formula of the precipitate formed as a result of the reaction between formalin and Fehling’s solution?

Formic/Methanoic Acid (HCOOH)

(Part 5) What is the color, name, and formula of the carboxylic acid formed as a result of the reaction between formalin and Fehling’s solution?

Light Blue (Upper Layer: Benzaldehyde, Lower Layer: Fehling’s Solution)

(Part 5) What is the color of the benzaldehyde and Fehling’s solution mixture?

Dark Blue

(Part 5) What is the color of the acetone and Fehling’s solution mixture?

Formation of white crystals

(Part 6) What can be visibly observed during the auto-oxidation of benzaldehyde?

Benzoic acid (C6H5COOH)

(Part 6) What is the final product when benzaldehyde is auto-oxidized?

Iodoform test for methyl ketones

(Part 7) What is the name of this test?

Acetone (CH3COCH3)

(Part 7) What is the sodium hydroxide and iodine added to?

10% Sodium Hydroxide (NaOH) Solution, Iodine (I2)

(Part 7) What is added to the acetone?

Yellow Iodoform (CHI3)

(Part 7) What is the positive result of the reaction between sodium hydroxide, iodine, and acetone?