EXP 14: Properties of Acetamide & Urea

Urea (NH2CONH2)

Urea (NH2CONH2)

Name and formula of the chief decomposition product resulting from metabolism of nitrogenous materials in the body

Instead of OH it is NH2

How do carboxylic acids and acid amides differ?

Acetamide (CH3CONH2)

(Part A) What is the name and formula of the acid derivative?

6 M Sodium Hydroxide (NaOH)

(Part A) What is the first reagent added to the acetamide (CH3CONH2)?

Ammonia (NH3)

(Part A) What is the gas produced when acetamide and sodium hydroxide react?

Urine-Like Odor

(Part A) What is the odor of the gas produced when acetamide and sodium hydroxide react?

Red to Blue

(Part A) What color does the litmus paper turn when placed above the reaction of acetamide and sodium hydroxide?

Ammonia Gas (NH3) and Sodium Acetate (CH3COONa)

(Part A) What are the two products of the reaction of acetamide and sodium hydroxide?

CH3CONH2 + NaOH —> CH3COONa + NH3

(Part A) What is the chemical equation of the reaction of acetamide and sodium hydroxide?

Concentrated Sulfuric Acid (conc. H2SO4)

(Part A) What reagent is added after the reaction of acetamide and sodium hydroxide?

Sodium Acetate (CH3COONa)

(Part A) Which product of the reaction between acetamide and sodium hydroxide reacts with the concentrated sulfuric acid?

Acetic Acid (CH3COOH)

(Part A) What is the organic product produced between the reaction of sodium acetate and concentrated sulfuric acid?

Vinegar Odor

(Part A) What is the odor of the reaction between sodium acetate and concentrated sulfuric acid?

Acetic Acid (CH3COOH)

(Part A) What is the name and formula of the product of hydrolysis of acetamide?

Sodium Nitrite (NaNO2)

(Part B) What is the name and formula of the reagent initially added to the acetamide?

First Test Tube: Acetamide (CH3CONH2) + Water (H2O) + Sodium Nitrite (NaNO2)

Second Test Tube: Concentrated Sulfuric Acid (H2SO4) + Water (H2O)

(Part B) What are in the 2 test tubes placed in the ice bath?

Sodium Nitrite (NaNO2) and Concentrated Sulfuric Acid (H2SO4)

(Part B) What are the two chemicals that react FIRST after the two test tubes are mixed?

Nitrous Acid (HNO2)

(Part B) What is produced from the reaction of HCl and Sodium Nitrite?

NaNO2 + H2SO4 —> HNO2 + NaSO4

(Part B) What is the chemical equation for the reaction between sodium nitrite and concentrated sulfuric acid?

Nitrous Acid (HNO2)

(Part B) What does the acetamide react with?

Acetic Acid (CH3COOH)

(Part B) What is the organic product that the reaction between the nitrous acid and acetamide yields?

Nitrogen Gas (N2)

(Part B) What is the gas that the reaction between the nitrous acid and acetamide yields?

HNO2 + CH3CONH2 —> CH3COOH + N2 + H2O

(Part B) What is the chemical equation for the reaction between the nitrous acid and acetamide?

Formation of Urea Nitrate

What is the name for Chemical Properties of Urea (Part 1)?

Concentrated Nitric Acid (HNO3)

(Part C.1) What is the reagent added to urea?

Urea Nitrate (NH2CONH2 * HNO3)

(Part C.1) What does the reaction between urea and nitric acid yield?

Formation of a White Crystalline precipitate

(Part C.1) What is the visible observation of the reaction between urea and nitric acid yield?

NH2CONH2 + HNO3 —> NH2CONH2 * HNO3

(Part C.1) What is the chemical equation for the reaction between urea and nitric acid?

Formation of Urea Oxalate

What is the name for Chemical Properties of Urea (Part 2)?

Saturated Oxalic Acid ((COOH)2)

(Part C.2) What is the reagent added to urea?

Urea Oxalate (NH2CONH2 * (COOH)2)

(Part C.2) What does the reaction between urea and oxalic acid yield?

Formation of a White precipitate

(Part C.2) What is the visible observation of the reaction between urea and oxalic acid?

NH2CONH2 + (COOH)2 —> NH2CONH2*(COOH)2

(Part C.2) What is the chemical equation for the reaction between urea and oxalic acid?

Formation of a Biuret

What is the name of Chemical Properties of Urea (Part 3)?

Biuret (NH2CONHCONH2)

When urea is heated above its melting point, what is the new compound it forms?

Ammonia Gas (NH3)

What gas is evolved from heating urea?

Peptide Bond (CONH)

What is the bond present in biuret?

Intensely Heated

(Part C.3) What is done to urea?

Pyrex Test Tube

(Part C.3) What is the name of the vessel urea is placed in?

Red to Blue

(Part C.3) What color does the reaction turn the litmus paper?

NH2CONH2 —Heat—> NH2CONHCONH2 + NH3

(Part C.3) What is the chemical equation for the reaction?

Biuret Test

What is the name of Chemical Properties of Urea (Part 4)?

Biuret Test

What is the test used for the presence of urea?

Violet

What is the color of a positive reaction in the Biuret Test?

Blue

What is the color of a negative reaction in the Biuret Test?

Dilute Sodium Hydroxide (NaOH) & Copper Sulfate (CuSO4)

(Part C.4) What are the components of the Biuret’s reagent?

Solution turns violet (positive reaction)

(Part C.4) What is the visible observation of the reaction between biuret and copper sulfate?

Solution turns blue (negative reaction)

(Part C.4) What is the visible observation of the reaction between unheated urea and copper sulfate?

Reaction of Nitrous Acid on Urea

What is the name of Chemical Properties of Urea (Part 5)?

Dilute Hydrochloric Acid (HCl) & Sodium Nitrite (NaNO2)

(Part C.5) What are the 2 reagents added to urea?

Dilute Hydrochloric Acid (HCl) & Sodium Nitrite (NaNO2)

(Part C.5) What reacts first?

Nitrous Acid (HNO2)

(Part C.5) What is the main product for the reaction between sodium nitrite and hydrochloric acid?

NaNO2 + HCl —> HNO2 + NaCl

(Part C.5) What is the chemical equation for the reaction between sodium nitrite and hydrochloric acid?

Nitrous Acid (HNO3)

(Part C.5) What is the product of the reaction between sodium nitrite and hydrochloric acid that urea reacts with?

Nitrogen Gas (N2)

(Part C.5) What is the gas produced between the reaction of urea and nitrous acid?

Carbonic Acid (H2CO3) and Water (H2O)

(Part C.5) Aside from nitrogen gas, what are the other products formed from the reaction between urea and nitrous acid?

(NH2)2CO + HONO —> 3HOH + H2CO3 + N2

(Part C.5) What is the chemical equation for the reaction between urea and nitrous acid?

Formation of small bubbles (which is N2)

(Part C.5) What is visible observation of the reaction?

Reaction of Sodium Hydroxide on Urea

What is the name of Chemical Properties of Urea (Part 6)?

Sodium Hydroxide (NaOH)

(Part C.6) What is added to urea?

Ammonia Gas (NH3)

(Part C.6) What is the gas produced between the reaction of urea and sodium hydroxide?

Sodium Carbonate (Na2CO3)

(Part C.6) Aside from ammonia gas, what is the other product formed by the reaction of sodium hydroxide and urea?

NH2CONH2 + 2 NaOH —> Na2CO3 + 2 NH3

(Part C.6) What is the chemical equation for the reaction between sodium hydroxide and urea?