oxygen level?

Question

If we undergo a reaction that can produce oxygen, and we collect the oxygen in a gas jar. How do we know if we have collected a full gas jar of oxygen? I don't know/

As pure oxygen must be got, we could not use a syringe.

If the gas is chlorine, we can put a pH paper near the open of the gas jar until the pH paper turns red and then white. But how about oxygen?

Answer 1

Lancenigo di Villorba (TV), Italy

SEE AT THE ENDINGS....

YOUR QUESTION
You offered several arguments, so I need to re-formulate your question before I show my reasonings.
I think you might ask :"Once a chemist led a chemical reaction able to develop any gas matter, is there some simple and valuable lab's test to define its own chemical nature? Moreover, can do these test distinguish the gas among Oxygen and Chlorine?".

HISTORICAL NOTE
As I written, I think you need for simple essays able to reveal Oxygen or Chlorine.
The previous answerer suggested you a simple test seeking for Oxygen : this gas should re-ignite wood's splint's as it does for warm candles (e.g. A. L. Lavoisier's remark, a famous french chemist lived in the XVIII century).

LAVOISIER AND OXYGEN
Once Lavoisier met the english scientist J. Priestley, the second man communicated to the first one is own researches on a new gas matter.
Lavoisier understood the powerful of this studies and he desired to replicate it : once he get success, he planned new and more complicated instances overcoming to very important findings.
Instead Priestley attributed his own overcomes by applying elder Phlogiston Theory, Lavoisier was able to state the followings :
-) the new gas is related to chemical composition of air itself, so air isn't a chemical compound while it results a gas mixture ;
-) the new gas is related to any combustion events, e.g. it interests wood, coal, etc. ;
-) the new gas is related to Calcination experiments, e.g. the heat-processes ale to convert Metal's Dusts in Brittle Calx ;
-) the new gas is involved in animal breathing, so he state the similarity between this phenomenon and combustion itself ;
-) the new gas cannot be broken in simpler chemical matters, so Lavoisier defined it a Chemical Element.
Starting from the invariance of the total mass inside a closed chemical reacting system (e.g. the most known among the Lavoisier's Principles), Lavoisier led the Phosphorous burning retrieving a white solid matter (e.g. Phosphorous Oxides) WHICH RESULTED HEAVIER THAN PHOSPHOROUS ITSELF, hence Phosphorous Combustion cannot involve Phlogiston since the latter was assumed as leaving matter, since the latter was assumed to diminute the Product's Mass.
Starting from the chemical properties of Combustion and/or Calcination's Products, Lavoisier offered the distiguishment among Metals and Non-Metals : the former stuffs should lead to Burnt Products having Basic Nature while the second substrates should give Acidic ones.
Finally, Lavoisier thought that any Chemical Compound having Acidic Nature (e.g. he referred to any Acid) should contain Oxygen atoms.

DAVY AND CHLORINE
In the second half of XVIII century, a swedish pharmacist (C. W. Scheele) executed some experiment upon an ore called MAGNISIA NIGRA, e.g. nowadays pyrolusite or Manganese Dioxide MnO2. He dipped the ore in an acidic solution of SPIRITUS SALI as the acidic aqueous solutions were defined : a gas-stream lift up

MnO2(s) + 4 HCl(aq) ---> MnCl2(aq) + Cl2(g) + 2 H2O(aq)

and Scheele collected it in the Hale's apparatus.
Scheele reported the gas shown a pale coloration while it resulted ABLE TO DESTROY COLORATION's CLOTHes.
Instead he understood the chemical nature of the ore and he predicted the existence of a new metal (e.g. Manganese as named by Scheele himself), Scheele interpreted his findings by applying Phlogiston's Theory : Scheele held to sink the Phlogiston inside the Acidic Liquid.
DE-PHLOGISTICATION on the Acidic Reactive.
Once he sent his experimental reports to Lavoisier himself, the french chemist suggested to Scheele to dename the Acid like MURIATIC ACID : in his turn, Scheele communicated his discoveries on the OXY-MURIATIC ACID since he thought to lead the de-phlogistication of the Muriatic Acid.
Lavoisier stated the ACID's SYNTHESIS in the following terms "any Acidic Compund have to contain some Oxygen amounts", so he failed to understand the composition of Muriatic Acid. One later the succeding one, Lavoisier wasn't able to resolve HCl, Lavoisier obtained nobody trace of Oxygen.
When Jacobin Party murdered the great scientist, his theories survived in the works of english chemists and some french other ones : among the latters there was C. L. Berthollet. This scientist was able to collect money to build a Chemical Lab in the Arcueil's City, where he and some assistants could execute their experiments.
Despite Lavoisier, Berthollet leaved the Oxygen's route and he produced some new chemical compounds based on the new gas matter, e.g. bleaching powder.
At the time, the chlorous fumes were engaged in the english textile industries (e.g. as Scheele predicted) but it stinks resulting a dangerous pollutant ; the Berthollet's powder acts in liquid medium avoiding the troubles. Among the young Berthollet's assistants there was J. Gay-Lussac : once he became an affirmed scientist, he executed several experiments in order to state its own chemical nature, as Lavoisier and Berthollet did in the previous times.
In the same years, the english H. Davy spent himself in this work and he brought his own challenge against Gay-Lussac.
Elsewhere the two great chemists were unable to form simpler chemical compounds, Davy lonely risked to define it as a Chemical Element : he led a fatal essay stating that glowing charcoal hadn't any effect on the unknown gas.
Since the gas shown a pale GREENISH COLORATION, Davy named it as Chlorine (e.g. from Greek Word CHLOROS).

DO YOU NEED FOR A SIMPLE CHLORINE's ESSAY?
How do I will do to seek for Chlorine in a glass-jar?
You suggested me the Litmus Paper but I prefer to preserve it to Acid-Base Exames...
On the other hand, I thought to any other ones...
In a glass-mouth I formed a Starch's aqueous solution where I add few drops of Lugol's solution (e.g. Iodine and Potassium Iodide in hydro-alcoholic medium...don't exaggerate!!) : I see a black-bluish liquid.
Now, I bring a light and thin paper-layer and I wet it with very few blackish liquid's drops....it's done!!
CHLORINE RESULTS ABLE TO DESTROY THE BLUISH TAINT

Cl2(g) + 2 KI(aq) ---> 2 KCl(aq) + I2(aq)
I2(aq) + 5 Cl2(g) + 6 H2O(aq) ---> 2 HIO3(aq) + 10 HCl(aq)

while Oxygen doesn't.
Warning!! The thin paper have to remain wetted since the above reactions need for water.

DO YOU NEED FOR A SIMPLE OXYGEN's ESSAY?
How do I will do to seek for Oxygen in a glass-jar?
May be you will appreciate it....
I bring a thin Zinc Metal's foil, so I take a Copper Metal's wire : this done, I manipulate it in order to form a Metal Bridge (e.g. did you know the italian scientist L. Galvani?).
I put the latter inside a great cotton's ball, so I wet this system by adding many and many drops of Phenolphtalein's aquoeus solution (e.g. Phenolphtalein is one of the most common Acid-Base Indicator).
Now, I introduce this wet metal-cotton's sphere inside the glass's jar : THE GREATER THE OXYGEN's PRESSURE, THE STRONGER THE PINKISH HUE APPEARING INSIDE THE COTTON MASS

2 Zn(s) + O2(g) + 2 H2O(aq) ---> 2 Zn++(aq) + 4 OH-(aq)
HInd(UNCOLOURED) + OH-(aq) ---> Ind-(PINK) + H2O(aq)

where Ind means MONOBASIC RADICLE OF PHENOLPHTALEIN when it is assumed as an acid like it behaves.

I hope this helps you.

Answer 2

Oxygen relights a glowing piece of wood called a splint.