Question

Unknown A

Benedict’s Test: Bluish color

Seliwanoff’s Test: Red

Fermentation Test: Bubbles

Iodine Test: no color change

Unknown A is _______because_______________.

Unknown C

Benedict’s Test: Red-orange precipitate

Seliwanoff’s Test: no color change

Fermentation Test: Bubbles

Iodine Test: no color change

Unknown C is _______because_______________.

Unknown E

Benedict’s Test: Blue-green color

Seliwanoff’s Test: no color change

Fermentation Test: Bubbles

Iodine Test: Purple/Black color

Unknown E is _______because_______________.

Unknown G

Benedict’s Test: Yellow/orange precipitate

Seliwanoff’s Test: Red

Fermentation Test: Bubbles

Iodine Test: no color change

Unknown G is _______because_______________.

Unknown K

Benedict’s Test: Yellow/orange precipitate

Seliwanoff’s Test: no color change

Fermentation Test: No Bubbles

Iodine Test: no color change

Unknown K is _______because_______________.

Answer 1

Benedicts test is used to detect the presence of aldehydes , ketones and hemiacetals and Benedict's reagents do not reacts or reacts slowly with starch (Iodinne test) because of small number of reducing sugar moieties occurs on the carbohydrate chains.

Seliwanoff's Test detects ketoses or aldoses present due to positve color change of red and pink . Red for ketoses and pink for aldoses

Fermentation test is used detect the fermentation reaction of carbohydrates able to produce acid ferment carbohydrates to be greater than alkaline carbohydrate and there will change of color from purple to yellow and the bubbles appearance due to formation of gas of acid carbohydrates

Iodine test to detect presence of strach in compound by adding iodine reagents and color change to puple or blue black

Unknown A :

Benedict's test: Bluish colour represents ,there is no sugar presents in it .

Seliwanoff’s Test: Reprensent positve to ketoses

bubbles appearance is due to  gas formation in tube of solution in the fermentation test .

iodine test is used to find presence of strach with turn into bluish black colour

Therefore,The unKnown A is positive to selwanoff's test represents that ketoses is presents in it

UnKnown C:

Unkown C is positve to Benedict's Test as red-Orange precipitate is formed , it means that there is reducing sugar of 1-2% of reducing sugars of disaccarides/monosaccarides as selwanoff's test is negative , so it is neither aldoses or ketoses and fermentation test has bubbles appearance is due to  gas formation in tube of solution and there is no presence of starch in it according to iodine test.

UnKnown E

Upon bluish green color of benedict's test represents 0.1-0.5% of reducing sugar presents in compound E , due to negative selwanoff's test (i.e) no colour change shows that it is neither aldoses or ketoses derivative and iodine test shows that there is some strach present in the reducing sugar unkown E is positive to iodine test and there is a bubbles appearance of gas in it

Unknown G

Benedict's test shows that there is presence of 0.5-1.5 % of reducing sugar present in it with ketoses derivative because red appearnce of selwanoff's test represents ketoses present in it , if it is pink in color then aldoses present in it.Therefore, 1-1.5% of reducing ketoses derivative with negative to iodine test (absence of strach) and bubbles appearance is due to  gas formation in tube of solution

Unknown K

Benedict's test shows there is presence of 1-1.5% of reducing sugar of mono/di saccarides with neither aldoses or ketoses derivative in it and no presence of starch and no positive carbohydrate fermentation present compound K