PCOG LAB EXP. 6 &7 Flashcards
(25 cards)
Acidity of unripe fruits and leaves are due to?
Organic acids
Of the white variety of aliphatic and aromatic organic acid contained in higher plants, one group of aliphatic acids generally known as _____ is distinguished be the reason of its wide distribution and physiological function
Plant acids
The best known of these plant constituents plant acids are?
Oxalic acid, Tartaric acid, malic acid, citric acid, and succinic acid
Calamansi is fairly sour and very much used as a seasoning and for making what?
“ade”
Less known but of equally wide distribution and importance are plant acid such as
Isocitric acid, fumaric acid, oxaloacetic acid, and ketoglutaric acid
The calamansi fruit is crushed with____ and use for cleansing the hairs
Gogo
Objectives of experiment number 6
To extract citric acid from calamansi juice
To determine the physical and chemical properties
What is the plant sample for experiment number 6 and its scientific name
Calamansi fruit (Citrus mitis Blanco)
What are the reagents used in experiment number 6
10% sodium hydroxide solution
10% calcium chloride solution
5% calcium chloride solution
5% lead acetate
Denige’s reagent
2% potassium permanganate solution
Resorcinol
Sulfuric acid
Procedure for the extraction of citric acid from calamansi
(a) Squeeze the juice from 10 big and green fruits of “Kalamansi” and strain through muslin.
(b) Measure the volume of the juice and add strong caustic soda solution carefully until the reaction is slightly alkaline.
(c) Filter and for every 10-ml of the juice- add 5 ml of 10% solution of calcium chloride. Heat to boiling; filter off while hot on a filter-pump (use filter paper).
(d) Wash the precipitate with a little boiling water, drain well and dry in air. Weigh and add the requisite amount of sulfuric acid. (1-gram citrate requires 15 ml of 1 N sulfuric acid).
(e) Allow the mixture to stand for short time, filter and concentrate the filtrate in an evaporating dish on a water bath. Crystals of citric acid separate out on concentrating considerably. If for any reason insufficient sulfuric acid has been added, some calcium citrate may separate out first on concerntration. If so, add a few drops of sulfuric acid, filter and continue to concentrate.
(f) Drain off the citric acid on a filter paper. Compute for the percentage yield. Submit the crystals collected.
How many tests are present specifically a chemical test in experiment number 6
3
Test for citric acid letter A procedure
Prepare 1% solution of citric acid, neutralize with caustic soda or 10% sodium hydroxide solution then divide into three test tubes and make the following test
Procedure for chemical test for citric acid a number one
Add 5% calcium chloride solution heat to boiling and know the solubility of calcium citrate in cold and in hot water
Procedure for test for citric acid A number 2
Add 5% lead acetate solution and divide into two portions. To one portion, add an equal quantity of acetic cid and warm. Observe the result
Test for citric acid letter b procedure
Take 5 ml of a 2% solution of citric acid and a 3 ml of denige’s reagent. Boil and add 2% potassium permanganate solution and observe the different changes produced
Test for citric acid letter c procesure
Heat gently a few crystals of citric acid for some time with equal weight of resorcinol and a few drops of concentrated sulfuric acid. Add an excess of alkaline and observed and fluorescence shown by the solution
What are the reagents used for chemical test letter A for experiment number 6
1% solution of the citric acid and caustic soda
What are the reagents used in the test for citric acid a number one
5% calcium chloride solution
What is the reagent used in test for citric acid a number 2
5% lead acetate solution
The agent present in experiment number 6 test versitic acid letter b
2% solution of citric acid
Denige’s reagent
2% potassium permanganate
The reagents in despacitric acid literacy
Citric acid crystals
Resorcinol
Sulfuric acid
Is a very general one with embraces all the money and varied combinations of sugars and aglycones
Glycoside
These plant pigments generally containing y-benzopyrone nucleus
Flavonoids
Lavonoids includes
Anthocyanins
Leukoanthocyanins
Catechins
Aurone
Calchone
