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Why is it necessary to keep the standard solution in a clean and dry reagent bottle?
Cychan
Standardized Sodium Hydroxide (NaOH), as most laboratory chemicals should be stored in a sealed bottle to avoid evaporation of the Water portion, which in turn would increase the concentration of the NaOH over time. (this can be observed experimentally by placing a drop of the NaOH(aq) solution on a safe surface and allowing it to evaporate. The H2O(l) will evaporate leaving NaOH(s) behind in the form of white crystals.)
Additional advice which is important with NaOH in-particular is to store the solution in a bottle that does not use a (ground) glass stopper. This is because NaOH dissolves glass. When in low concentrations this process precedes rather slowly, and may simply make the glass-on-glass stopper joint difficult to open. Stronger solutions are capable of freezing the joint permanently! (for an extreme example Sodium Hydroxide heated above its melting point to the liquid phase readily dissolves solid glass into a solution! This is not an experiment that should be attempted but only used for comprehension of why the phenomena occurs)
Wiki User
∙ 12y ago
Wiki User
∙ 13y agoThe bottle should be stoppered to protect the NaOH solution from CO2 in the air. A rubber stopper should be used because a strongly alkaline solution tends to cement a glass stopper so firmly that it is difficult to remove.
Wiki User
∙ 11y agoA standard solution is one of known chemical composition and concentration. If it were placed in a wet reagent bottle it would become contaminated by whatever was in the bottle previously. This decreases the validity of results.
Wiki User
∙ 16y agoTo avoid contamination and dilution, in order to guarantee a constant concentration.
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What is the difference of dropping bottle and reagent bottle?
The reagent bottle is not used for dropping, having only a common stopper.
Uses of reagent bottle?
It is a heavy glass bottle (unlikely to break or react with the reagent chemicals) used to store moderate amounts of laboratory chemicals (reagents)
Why are some reagent bottle colored?
Some solvent or chemicals are sensitive to light, and they get oxidised when they are exposed to it.
What is reagent bottle and how is used?
used as a container where you put chemicals that can't be thrown in the sink.
Why should screw cap of a reagent bottle be placed bottom up on the table?
If the cover of a reagent bottle is placed on a table with the bottom down, it can pick up material from the table which would contaminate the contents of the reagent bottle after the cap is put back on the bottle.
Why is it important not to pipette a reagent solution directly from bottle of a reagent stock solution?
Contamination. Your stock solution has a known molarity and should not be contaminated with anything. Even a "clean" pipette tip. Its just good lab etiquette.
What is the difference of dropping bottle and reagent bottle?
The reagent bottle is not used for dropping, having only a common stopper.
Uses of reagent bottle?
It is a heavy glass bottle (unlikely to break or react with the reagent chemicals) used to store moderate amounts of laboratory chemicals (reagents)
Why are some reagent bottle colored?
Some solvent or chemicals are sensitive to light, and they get oxidised when they are exposed to it.
Why is it important to a dry and clean spatula in scooping solid chemicals from reagent bottle?
This standard procedure -dry and clean spatula in scooping solid chemicals from reagent bottle- should prevent contamination of - and exposure to dirt and humidity to - the other chemical reagents.
What is reagent bottle and how is used?
used as a container where you put chemicals that can't be thrown in the sink.
Why should screw cap of a reagent bottle be placed bottom up on the table?
If the cover of a reagent bottle is placed on a table with the bottom down, it can pick up material from the table which would contaminate the contents of the reagent bottle after the cap is put back on the bottle.
A dry and clean spatula is used to spoon out small amount of solid from a reagent bottle?
This is to prevent contamination of the remaining reagent in the bottle.
The hcl solution has a lower concentration than what is indicated on the reagent bottle Will the result indicate the presence of more or less moles of base in the antacid?
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Why anthrone reagent needs to be kept cold before using?
Anthrone reagent is prepared in concentrated sulfuric acid. Adding reagents to acid causes immediate dissociation of the reagent and releases heat. If your solution weren't cold, it could generate enough heat to blow out of the flask or bottle.
What type of bottle is used for storing acids and bases?
A Reagent Bottle.
Why should the spatula used for spooning solid chemical from a reagent bottle be clean and dry?
So you don't get water, dirt or other contaminants in the reagent bottle. The reagent bottle should contain chemicals that are as pure as possible. If each person put a dirty spatula in the bottle, the reagent bottle would very quickly accumulate all kinds of junk, ruining the chemicals inside or causing hazardous chemical reactions.
