COMMON LABORATORY TECHNIQUES AND APPARATUSES Flashcards
To dispense chemicals, read the label at least twice before removing any chemical from the reagent bottle.
TRUE
When heating a liquid in a test tube, the test tube should be more than two-thirds full, moved continuously in and out of the coll flame at a 45⁰ angle, mostly near the top of the liquid.
FALSE
when heating a liquid in a test tube, only one third of test tube should be filled.
to heat tube gently and uniformly, move the test tube around the flame
The volume of a liquid should be read at the bottom of the meniscus.
TRUE
A litmus paper test for the acidity or basicity of a solution is done by dripping a stirring rod into the solution and using this to wet the litmus paper.
False
Given statement is false because for litmus paper test for the acidity or basicity of a solution is done by dipping in litmus paper into the solution and take out immediately.
If we use red litmus paper and it turns blue then the solution is basic and if do not change color then solution is acidic in nature.
If we use blue litmus paper and it turns red then the solution is acidic and if do not change color then solution is basic in nature.
Water or glycerol should be applied to the glass tubing and the hole in the rubber stopper before inserting the glass tubing.
TRUE
Transfer liquids and solutions from a reagent bottle or beaker with the aid of a stirring rod.
TRUE
Never touch, taste, or smell unless specifically told to do so.
TRUE
If uncertain as to how to dispose a chemical, dumping it to the sink followed by copious amount of water is a safe disposal procedure.
FALSE
Disposing the chemical in a sink is the most uncanny things one can do in a lab. Therefore it is advisable to know the disposal technique or rather store it in a container with visible labels such as liquid waste, solid waste, acid waste, organic waste etc.
A centrifuge machine should be balanced with an even number of centrifuge/test tubes placed across the rotor from one another, with equal volumes of liquid.
TRUE
The minimum number of centrifuge tubes in a centrifuge machine during its operation is one.
FALSE
two
Never place reagents directly onto the weighing pan of a balance, always use weighing paper, a beaker, or some other container.
TRUE
To transfer a solution, the stirring rod touches the delivery point of the reagent vessel and the wall of the receiving vessel.
TRUE
An open flame is the heat source for heating or evaporating flammable liquids.
FALSE
Most chemicals used in the experiments can be discarded in the sink.
FALSE
