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7 votes
Accepted

What does the blue square on a volumetric flask mean?

One of the ASTM International requirements, formerly known as American Society for Testing and Materials, is: ASTM E288 - 10 Standard Specification for Laboratory Glass Volumetric Flasks. 4.5.3 ...
AChem's user avatar
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8 votes

What does the blue square on a volumetric flask mean?

The etch mark truly could be blue (or in an other color). But (arguably) it is more common to find such an etch mark in plain white on glass ware, for instance beakers, or flasks, or bottles, or ...
Buttonwood's user avatar
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5 votes
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Percentage Yield

Let: A = $\ce{CaC2}$ B = $\ce{C2H2}$ $$\mathrm{yield}=\frac{m_\mathrm{B}}{m_\mathrm{B}^*}=\frac{m_\mathrm{B}}{n_\mathrm{B}^*\;M_\mathrm{B}}=\frac{m_\mathrm{B}}{n_\mathrm{A}\;M_\mathrm{B}}=\frac{m_\...
Sam202's user avatar
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11 votes

Is nitroglycerin synthesis within human digestive system from eating soap possible?

First of all, you don't need to eat soap to get glycerin in your system. Fats are broken down by digestion into glycerin and fatty acids. Glycerin is also available commercially as a cough syrup and ...
Level River St's user avatar
21 votes

Is nitroglycerin synthesis within human digestive system from eating soap possible?

According to the metabocard at HMDB — Nitroglycerin, nitroglycerin is only found in individuals that have used or taken this drug. No known metabolic pathways for glycerin lead to nitroglycerin either....
andselisk's user avatar
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0 votes
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Does a steel pestle corrode while pressing soot?

Yes. Further experimentation with non-magnetic $\ce{CaCO3}$ also resulted in slightly ferromagnetic flakes. Harder materials (which are not reactive nor magnetic) produce the effect with less effort, ...
Paul Kolk's user avatar
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2 votes
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Atomization and excitation in AES

This is a good question as to why graphite furnace in atomic absorption cannot be used for atomic emission spectroscopy. Keep in mind that the temperature of the graphite furnace is quite high, higher ...
AChem's user avatar
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1 vote

Atomization and excitation in AES

Graphite furnaces can indeed be used for the purposes of atomizing a sample for atomic absorption spectroscopy, see the Wikipedia page on the subject. However, and what I would like to clarify, is ...
kneez's user avatar
  • 86
2 votes

How to identify salts using mutual reactions

I will try to follow Poutnik's suggestion. And try to recognize the solutions without using external reagents. The only allowed mixtures are made by mixing two unknown solutions. Let's consider for ...
Maurice's user avatar
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1 vote

How to identify salts using mutual reactions

This task is a typical sort of problem used in the International Chemistry Olympiads. It allows you to quickly judge if the candidate knows the main reactions of usual ions. It looks like you have ten ...
Maurice's user avatar
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2 votes
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How to identify salts using mutual reactions

I understand the task as there cannot be used external means, just reactions between contents of different tubes. I can be wrong, of course. In such a case, the optimal solution would be rather in the ...
Poutnik's user avatar
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