biochem POST LAB TEST Flashcards
mEMORIZE
The liquid that passes through the filter paper during filtration
filtrate
The filtration method is not suitable for separating soluble solids from a liquid.
True
The eye is kept at the 1________ meniscus to get the volume of a colorless solution and at the 2_______ meniscus to know the volume of a colored solution.
1 lower, 2 upper
The gas used in the lab as a source of fuel is ______ gas.
butane
Adjusting the ________ of the Bunsen burner changes the height of the flame.
gas valve
When using the Bunsen burner for heating, the flame should be a ________ flame.
None Luminous
_______ Heating is a safer way of heating non-flammable liquids than a water bath or a steam bath.
Direct
It is proper to inspect the rubber tubing attached to the Bunsen burner for cracks or any other defects
True
Paper may be used to transfer solid substances to a small-mouthed container.
True
The _______ of the Bunsen burner is adjusted to regulate the flow of the air and to produce the desired color or nature of the flame.
Colar
The solid product that remains on the dish after evaporation is called ________.
Residue
__________ is a basic purification method used in the laboratory that relies on a porous material and gravity.
Decantation
Before transferring solid chemicals, the container to be used must be clean and damp to avoid contamination.
False
A solid substance formed during a chemical reaction is called the _________.
precipitate
It is necessary to cover the test tube with a cork when heating solutions over direct flame.
False
The solid substance that remains on the filter paper after filtration is called _______.
Residue
The Bunsen burner to be used must be placed near the combustible materials and chemicals.
False
A clean and dry spatula can be used to spoon out the solid chemicals from its container.
True
The proper way to light a Bunsen burner is to slowly open the gas valve and then bring a lighted match near the tip of the burner.
True
Test for Unsaturation
Von Bayers Test and Bromine Test
Alkanes are _______, Compared to the other 2
Saturated
Alkanes and Alkynes are __________
Unsaturated
_______ Contains carbon-carbon double bond but is not considered unsaturated
Benzene ring
Von Bayers test:
Uses __________ __________ or (______) to oxidize alkenes and alkynes
Potassium Permanganate (KMnO4)
Von Bayers test:
Product -
Manganese Dioxide (MnO2)
Removes violet color and makes it brown positive for unsaturation
Bromine Test:
_________ is added to alkenes and alkynes
Bromine
Bromine Test:
Product - _______________ and ________________
Dibromoalkanes and Tetrabromoalkanes
if it disappears, then it is positive for unsaturation
Test for alcohols and phenols
Finds Hydroxyl groups -
Boardwell - wellmans test
Labels Hydroxyl groups into 1,2,3* -
Lucas test
Specified to detect phenols -
Ferric chloride
Boardwell - wellmans test:
Uses __________ _________ or (________) Dissolved in ________ _______ That makes ___________ ___________ or (_____)
Potassium dichromate (KR2CR2O2) +
Sulfuric acid = Hexavalent Chromium or (CR6+)
Boardwell - wellmans test:
1* and 2* oxidizes into 1_________ _____ and 2_________ respectively
this is the product CR6+ Becomes 3________ ____ OR (_____)
1- carboxylic acid, and 2- ketones, 3- Chromic Ions, (CR3+)
Green color
Boardwell - wellmans test:
Phenols will produce _____________
benzoquinone
brown color
Boardwell - wellmans test:
What will happen to 3* or tertiary alcohols
Nothing lol. They’re not affected
Lucas Test:
Uses 1__________ _________ ______ and 2______ _________
1- Concentrated Hydrochloride acid, 2- Zinc chloride
Lucas Test:
Converts 1, 2, 3* Into ______ ______
alkyl groups
emulsion = positive
Lucas Test:
From 1* to 3* the reaction becomes more _______
Rapid
Ferric Chloride test:
(_____) or___ _______ ________ solution is needed on phenols
(Fe3+) or 2% Ferric Chloride solution
Ferric chloride:
The product is a color change from Orange to ______
Violet
Test for aldehydes and Ketones
2,4 DNP Test
Tollens Test
2,4 DNP Test:
1_______ Carbonyl groups (aldehydes and ketones) by adding 2_____________________
1- Detects, 2- Dinitrophenylhydrozine
2,4 DNP Test:
If , _____________________ is found, it tests positive for both ketones and aldehydes. Becomes a yellow or orange-red precipitate.
2,4 Dinitrophenylhydrozone
Tollens test:
__________ aldehydes and ketones,
distinguishes
Tollens test:
Based on that, aldehydes can _________, and ketones cannot
oxidize
Tollens test:
______ _________ ________ or ___(____)___ is added to a substance
Silver Ammonia Complex OR Ag(NH3)2+
Tollens test:
Silver ion is reduced to ________ ______
elemental silver
Silver mirror = positive test = aldehydes
Test for Carboxylic acids
Sodium Bicarbonate test
Sodium Bicarbonate test:
1______ _________is produced in the presence of 2___________.
1- Carbon dioxide, 2- effervescence
effervescence = Positive test
Sodium Bicarbonate test:
________ ________ _________ is added to the test tubes
Sodium bicarbonate Solution
