Experiment #9: HYDROLYSIS OF SUCROSE (ACID VS BASE)

Question 1

Formula of Sucrose

Answer 1

C12H22O11

Question 2

Characteristics of Sucrose

Answer 2

Soluble in water, slightly soluble in alcohol and ether, crystallizes in long slender needles

Question 3

Sucrose is dextrorotatory which means

Answer 3

Rotating the plane of polarized light to the right

Question 4

Upon hydrolysis it yields a mixture of

Answer 4

Glucose and Fructose

Question 5

Glucose and Fructose are levorotatory which means

Answer 5

Plane of polarized light to the left

Question 6

The mixture obtained in the hydrolysis of sucrose is known as

Answer 6

Invert sugar

Question 7

Processs of hydrolysis of sucrose

Answer 7

Inversion

Question 8

Inversion is carried on in the human intestine through the aid of the enzymes known as

Answer 8

Invertase and Sucrase

Question 9

Sucrose is extracted chiefly from _____ and _____ and is commonly called_____

Answer 9

Sugarcane, Sugar beet, Cane Sugar

Question 10

When heated to temperatures above 180C (356F) sucrose becomes the amorphous, brown, syrupy substance called

Answer 10

Caramel

Question 11

Hydrolysis of sucrose is used to

Answer 11

Convert sucrose (non-reducing disaccharide) to glucose and fructose (reducing monosaccharide)

Question 12

The only non-reducing disaccharide that does not reduce Cu+² solution (Benedict’s and Fehling’s test)

Answer 12

Sucrose

Question 13

Sucrose is the only non-reducing disaccharide so it does not reduce Cu+² solution because

Answer 13

The glycosidic bond is formed between the two hemiacetal bonds, so there is no free aldehydic or ketonic group to give positive reducing properties.

Question 14

This bond can be hydrolyzed and the individual components of _______ are the able to give ________ test

Answer 14

Sucrose(glucose +fructose), positive reducing

Question 15

Fehling’s A composition

Answer 15

Blue colored aqueous solution of copper (II) sulfate (CuSO4)

Question 16

Fehling’s B composition

Answer 16

Colorless aqueous solution of potassium sodium tartrate (Also known as Rochelle Salt)

Question 17

Acidic (H2SO4) Observation

Answer 17

It turned to color red positive

Question 18

Basic (NaOH) Observation

Answer 18

Blue, Negative

Question 19

When sucrose goes through hydrolysis

Answer 19

The hydrolysis of sucrose generates an equimolar mixture of fructose and glucose, known as invert sugar

Question 20

Why hydrolysis of sucrose called inversion

Answer 20

It’s because sucrose produce equimolecular mixture of glucose and fructose. Sucrose is dextrorotatory and glucose & fructose is levorotatory

Question 21

Role of Sulfuric acid and Sodium Hydroxide

Answer 21

Catalyst
The rate of dehydration then accelerates as the acid heats up because the reaction is exothermic
2 chemicals compared as to which is the faster catalyst

Question 22

Reagent used in Hydrolysis of Sucrose

Answer 22

Fehling’s reagent