First Semester

Question 1

is a specific for detecting the presence of pentose sugars, such as ribose and xylose. It forms blue to green-colored compounds.

Answer 1

Bial’s Test

Question 2

used to identify the presence of starch.

Answer 2

Iodine test

Question 3

employed to detect reducing sugars, primarily monosaccharides like glucose. It involves the reduction of Cu(II) ions to Cu(I) ions, resulting in a red precipitate of copper(I) oxide.

Answer 3

Fehling’s test

Question 4

Similar to Fehling’s test, used to detect reducing sugars, including monosaccharides and some disaccharides. It produces a colored precipitate, ranging from green to red, depending on the amount of reducing sugar present.

Answer 4

Benedict’s test

Question 5

test is used to identify reducing sugars, with a focus on detecting maltose. It uses a solution of bismuth subnitrate, which forms a brown to black precipitate in the presence of reducing sugars.

Answer 5

Nylander’s test

Question 6

used to differentiate reducing monosaccharides from reducing disaccharides.

Answer 6

Barfoed’s test

Question 7

used to differentiate between ketose and aldose sugars. It forms a red color in the presence of ketose sugars

Answer 7

Seliwanoff’s test

Question 8

used to identify galactose. forms crystals

Answer 8

Mucic Acid Test

Question 9

used for the quantitative estimation of carbohydrates, particularly glucose. reacts with carbohydrates to form BLUE-GREEN COLOR

Answer 9

Anthrone test

Question 10

a specific test for ketohexoses, like fructose. It involves the formation of colored compounds when heated with sulfuric acid and resorcinol.

Answer 10

Moore’s Test

Question 11

general test for the presence of carbohydrates. It detects the presence of all types of carbohydrates by forming a purple color upon reaction with concentrated sulfuric acid.

Answer 11

Molisch Test

Question 12

the liquid or solution that passes through a filter paper or filter membrane during the process of filtration.

Answer 12

filtrate

Question 13

A solid that forms when two or more substances in a solution react chemically and result in the formation of an insoluble solid.

Answer 13

precipitate

Question 14

refers to the solid material that remains behind on the filter paper

Answer 14

residue

Question 15

Produced by the incomplete combustion wherein there is too much fuel than oxygen.

Answer 15

luminous

Question 16

Color of the flame is a bluish hue.
Does not produce soot
Result of a complete combustion

Answer 16

non-luminous

Question 17

Used to accurately measure and transfer small volumes of liquids.

Answer 17

Pipet

Question 18

Used for holding, mixing, and heating liquids. It has volume markings for approximate measurements.

Answer 18

beaker

Question 19

Used for heating, sterilizing, and performing various experiments by adjusting the flame intensity.

Answer 19

Bunsen Burner

Question 20

Placed on a ring stand to support a crucible during heating.

Answer 20

clay triangle

Question 21

Used in distillation setups to cool and condense vapor back into liquid.

Answer 21

condenser

Question 22

Used in distillation setups to contain the liquid to be distilled.

Answer 22

distilling flask

Question 23

Used for evaporating liquids and leaving behind solids in various experiments.

Answer 23

evaporating dish

Question 24

Used for mixing, heating, and storing liquids. Its conical shape allows for efficient stirring and reduced splattering.

Answer 24

Erlenmeyer flask

Question 25

Similar to the Erlenmeyer flask, used for mixing and heating liquids, often with a rounded bottom.

Answer 25

Florence Flask

Question 26

Used to control the shape and intensity of the Bunsen burner flame.

Answer 26

fishtail

Question 27

Used for stirring and mixing solutions in a laboratory setting, and also for transferring liquids

Answer 27

glass rod

Question 28

Used to channel liquids into containers with narrow openings.

Answer 28

funnel

Question 29

Used for various applications, such as connecting different pieces of apparatus in a laboratory setup.

Answer 29

glass tubing

Question 30

Used to accurately measure and dispense specific volumes of liquids.

Answer 30

graduated cylinder

Question 31

Provides support for various pieces of laboratory equipment during experiments.

Answer 31

iron stand

Question 32

Attached to the iron stand, it holds glassware, such as beakers, over a Bunsen burner.

Answer 32

iron ring

Question 33

Used to secure glassware to an iron ring or stand.

Answer 33

iron clamp

Question 34

Used for grinding and pulverizing solid substances into a fine powder.

Answer 34

mortar and pestle

Question 35

Used for heating substances at high temperatures, often for chemical analysis.

Answer 35

porcelain crucible

Question 36

Used to connect glassware in setups that require the transfer of gases or liquids.

Answer 36

rubber tubing

Question 37

Used to handle crucibles and other hot objects safely.

Answer 37

crucible thongs

Question 38

Used for holding small amounts of liquids or solids for experimentation.

Answer 38

test tube

Question 39

Test Tube Rack:

Answer 39

holds multiple test tubes upright for easy storage and observation.

Question 40

Provides a secure grip on test tubes when they need to be heated.

Answer 40

test tube holder

Question 41

Measures temperature accurately in laboratory experiments.

Answer 41

laboratory thermometer

Question 42

Used for precise preparation and dilution of solutions to a specific volume.

Answer 42

volumetric flask

Question 43

Provides a stable platform for heating containers over a Bunsen burner.

Answer 43

tripod

Question 44

Used to cover beakers or other containers to prevent contamination and evaporation.

Answer 44

watch glass

Question 45

what are the General Tests for the Presence of Carbohydrates

Answer 45

moolisch, moores, antrone

Question 46

is found to give a positive result for all carbohydrates. All the samples displayed the formation of violet rings in between the layers of the test solutions and the sulfuric acids. Thus, this test can be used to determine the general presence of carbohydrates.

Answer 46

molisch test

Question 47

it is used for detecting reducing sugars, Before anything else, it is established that all monosaccharides are reducing sugars, all polysaccharides are non-reducing sugars, while disaccharides can be either. In this experiment, only the glucose (monosaccharide) had a positive result via a change in color of the liquid. Hence, this test can be used to determine the presence of reducing sugars, that is, monosaccharides and a few disaccharides.

Answer 47

Moore's test

Question 48

formation on violet rings on glucose, sucrose, and starch

Answer 48

molisch test

Question 49

change of color from colorless to yellow and finally to a light orange. a slight odor of caramel was detected. while both starch and sucrose did not. what test is this and why did it result to this?

Answer 49

glucose is a reducing sugar, which is a monosaccharide all monosaccharides are reducing sugars and a few disaccharides are, while polysaccharides are not. Moore's test

Question 50

the three samples turned into varying shades of dark blue, dark green, and dark gray, but it overall centered around the bluish-green complex, indicating that they all have the presence of carbohydrates. Therefore, this test is used for detecting the general presence of carbohydrates.

Answer 50

anthrone's test

Question 51

what are the three general tests for carbohydrates are

Answer 51

molisch moores anthrones

Question 52

test for glactose in which is based on the formation of a crystalline dicarboxylic acid that is insoluble in dil. HNO3, a reaction that is unique to galactose and galactose compounds

Answer 52

mucic acid test

Question 53

yields positive results for galactose and lactose as the formation of white crystal are seen on bottom of the mixture, while the glucose does not.(monosaccharides produces precipitate that are soluble in water)

Answer 53

mucic acid test

Question 54

test for ketoses, fructose and sucrose are only the positive among the group

Answer 54

seliwanoff's Test

Question 55

test for pentoses, ribose is only the positive among the group

Answer 55

bial's Test

Question 56

why did the ribose turned blue during the bial's test

Answer 56

for the reason that it indicates the presence of pentose can only be triggered by dehydration, which in this case is caused by boiling.

Question 57

what are the specific tests for carbohydrates?

Answer 57

mucic acid test seliwanoff's test Bial's test iodine test

Question 58

what are the reducing sugars tests?

Answer 58

fehling's Nylander's tset Benedict's Picric acid test Barfoed's Test

Question 59

HNO3 oxidizes the aldehyde groups at C1 and primary alcoholic groups at C6 of galactose. This reaction yields mucic acid or galactric acid which is a fine white gritty crystal that is insoluble in water

Answer 59

Mucic acid test

Question 60

Test to Differentiate Helical Polysaccharides

Answer 60

Iodine test

Question 61

is a chemical test used to differentiate between reducing and non-reducing sugars. The test can also distinguish ketone functional group carbohydrates and water-soluble carbohydrates.

Answer 61

Fehling's Test

Question 62

t reveals that a sugar is reducing if the solution turns into the color black when heated and mixed with this reagent

Answer 62

nylander's test

Question 63

test determines whether a sugar is reducing if the results show a change in color from yellow to mahogany red.

Answer 63

picric acid test

Question 64

this test is to distinguish a reducing sugar from nonreducing by the formation of brick red precipitate.

Answer 64

Barfoed's test

Question 65

Why would glucose and maltose give positive results upon prolonged boiling with Seliwanoff’s reagent?

Answer 65

maltose is a disaccharide since it is made up of two alpha d glucose, in which the c1 of the first glucose is attached to the c4 of the second glucose. heating disaccharides yields a positive result. in the case of glucose, it is a an aldose. prolonged heating of glucose turns it into fructose by catalytic action of the acid.

Question 66

Why is boiling necessary in Bial's test

Answer 66

boiling is necessary in the bial's test, for the reason that the principle of the Bial’s test is the hydrolyzation of pentosans into pentoses. Specifically, the pentoses must be dehydrated and this can be done by boiling the solutions.

Question 67

Each polysaccharide tested gives different color results with the Iodine test. Explain the reason briefly.

Answer 67

because they vary in their structural motifs. The basic principle of this test is that iodine reacts with polysaccharides with helical or coiled structures and forms an absorbed compound that gives significant colors.

Question 68

What is the advantage of Benedict’s solution over Fehling’s solution?

Answer 68

it is more stable, easier to handle, and does not deteriorate quickly.

Question 69

What is the product formed when picric acid is reduced?

Answer 69

the product that is formed is picramic acid. The product is seen as a red precipitate and causes the solution to change color to mahogany red.

Question 70

Why is sucrose nonreducing

Answer 70

it does not have a free ketone and aldehyde groups

Question 71

a positive Molisch test:

Answer 71

presence of carbohydrates

Question 72

a positive Benedict’s test:

Answer 72

presence of reducing sugar.

Question 73

a positive Barfoed’s test after 10 minutes

Answer 73

presence of reducing sugar as both monosaccharides and reducing disaccharides would have already formed brick red precipitate.

Question 74

a positive Benedict’s test but negative Barfoed’s test in 5 minutes:

Answer 74

presence of reducing disaccharides