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3
votes
2answers
33 views

How to report pH values?

I have measured the pH in the water-soluble fraction of a powder. I weighed in a certain amount of powder and a certain amount of water, and extracted the water-soluble fraction. I then measured the ...
5
votes
1answer
20 views

Is the term carboreduction interchangeable with carbothermic reduction

I am currently studying reactions involving the reduction of metal oxides by carbon at high temperature to produce refractory carbides (such as $\ce{ZrC}$) following equations such as: $$\ce{ZrO_2 + ...
5
votes
2answers
130 views

What is actually a redox reaction?

I need to know what a redox reaction is. How could a redox reaction possibly be identified? Also, I have a confusion whether, $$\ce{H -> H+ + e-}$$ $$\ce{e- + Cl -> Cl-}$$ $$\ce{H + Cl -> ...
4
votes
1answer
43 views

What does it mean if a functional group has “higher priority” in terms of IUPAC naming of organic compounds?

What does "higher priority" mean exactly in the following statement from this wikipedia article (article name: "E-Z notation") on naming organic compounds in IUPAC nomenclature of organic compounds? ...
5
votes
1answer
51 views

Is there a name for the opposite reaction to the dissolution?

When atmospheric $\ce{CO2}$ reacts with water to form $\ce{H2CO3}$, this is called dissolution, isn't it? What term would you use for the opposite reaction when it occurs at atmospheric pressure (e.g. ...
0
votes
1answer
34 views

Significant Figures: To expand or not to expand? [closed]

4 * (2 + 2) = ? 4 * 4 = 20 (rounded to 1 significant figure) OR 4 * 2 + 4 * 2 = 16 2.0 * (0.5 + 0.5) = ? 2.0 * 1.0 = 2.0 OR 2.0 * 0.5 + 2.0 * 0.5 = 2
0
votes
1answer
36 views

When the terms diphosphate and pyrophosphate are used?

I read on Wikipedia article about pyrophosphate and it stated that pyrophosphate is also called diphosphate.But for example, why ADP is apparently called Adenosine Diphosphate but not Adenosine ...
3
votes
1answer
430 views

Definition of major, minor, and trace elements in analytical chemistry

What is the definition of major, minor, and trace elements in a sample? I am unable to find this anywhere on the internet. Is it something like: Major elements are those > 0.1 % Minor elements are ...
2
votes
2answers
263 views

What does oxidizing strength mean?

What does oxidizing strength mean? Does it mean the strength of a oxidation agent that is needed to oxidize the reduction agent, or does it just mean the tendency of a substance to lose electrons ...
5
votes
2answers
196 views

What is the word for how polyprotic an acid is?

What is the word to describe the number of acidic hydrogens an acid has? I am currently thinking something like "proticity", but I am not sure The use case world be for a table of things like this: ...
2
votes
2answers
114 views

Why is mercury used in thermometers?

I know it expands when hot and grows compact when cool (that's about all I know), but I suppose many other substances do, too. Also, and excuses for my ignorance, what the term used to describe the ...
2
votes
1answer
52 views

What is molecular system in general terms? What is a supramolecular system?

What is a molecular system in general terms? Could the solution of sugar in water be called a molecular system, if we were not interested in sugar-water interaction? Today Jean Marie Lehn told me ...
0
votes
2answers
70 views

Why is it written as “joule” and “J”?

Why is the unit joule is written as "joule" and "J", I mean what does "J" mean and what does "joule" mean.
6
votes
3answers
490 views

Why is introductory chemistry so non-rigorous?

In introductory chemistry books, courses, ... Many "definitions" contain words like: typically, most, often, likely, generally. I read since questions on this site mentioning different definitions ...
0
votes
0answers
23 views

impure substance vs mixture [duplicate]

Based on what I have found on the web they are the same. But chemists seem to use a colloquial terminology, by which if the ratio of two substances in a mixture is below --say-- 1/1000 or above ...
4
votes
1answer
28 views

What is the term for the amount of volume change at a phase boundary?

Apologies for the extremely basic question, but I would like to look up the amount by which the volume (or equivalently, density) of various substances changes when they freeze. However, I don't know ...
4
votes
2answers
1k views

What's Standardization, and why do it?

Surprisingly, there are very few resources online (outside of obscure lab pages) that explain exactly what standardization is (not even Wikipedia!). The context is the phrase standardize the titrant ...
0
votes
1answer
33 views

The proteins “eluted” or “were eluted”?

In describing proteins, I've written "the proteins detached from the [Ni-IDA] matrix and were eluted from the column" Should I use "were" or can something simply "elute" ?
2
votes
1answer
8k views

What's the difference between enthalpy of combustion and heat of combustion?

Wikipedia has two different pages for enthalpy of combustion and heat of combustion. Their definition is the same and they use the same symbol $\Delta H_c^\circ $ It says that enthalpies of ...
0
votes
1answer
45 views

Thermodynamics terminology

For the reaction $\ce{2C(s) + 3H2(g) -> C2H6(g)}$ , $\Delta H=-82 \text{ KJ/mol}$ , the amount of heat, which will be given out in the formation of 30g of ethane will be a) -82 KJ b) ...
1
vote
0answers
170 views

Difference between inorganic and organic semiconductors: electronic structure or configuration, or?

Organic semiconductors differ from inorganic semiconductors. In organic semiconductors the molecules are held together by weak van der Waals interactions and in inorganic semiconductors by covalent ...
2
votes
2answers
56 views

What does the commercial chemical composition notation “Percent dry, wet with water”mean?

I am not a chemist, I develop software. I'm hoping for a general explanation I can understand in order to assist me with a project I'm working on. Customers viewing a product online such as peroxide ...
1
vote
2answers
57 views

Redox reaction terminology

In the case of this redox reaction: $ \ce{ Cu SO_4 + Zn → Zn SO_4 + Cu} $ Is it correct to say that the sulfate reduces to the zinc? Or is it the whole molecule that is reducing? Or just the copper? ...
1
vote
1answer
95 views

Significant Figures in almost-scientific notation

For a homework assignment on significant digits, I have to find the number of significant digits in the number $0.40 \times 10^3$. I know that in scientific notation, the number of significant digits ...
2
votes
1answer
585 views

Difference between the terms “autocatalysis” and “(branching) chain reaction”

Is there a technical difference between the terms "autocatalysis" and "branching chain reaction"? They both seem to refer to something very similar, namely sequences of reactions in which one of the ...
6
votes
2answers
6k views

What is the difference between graphite oxide and graphene oxide?

I am considering making a sheet of graphene using the LightScribe technique and I have read that I need graphite oxide. However when I look up graphite oxide for sale, graphene oxide pops up. Are ...
3
votes
1answer
82 views

Is there a specific term for reactions of the form A + B → C + D?

I'm working with an abstract model of chemical reaction networks. In this model, some of the reactions have the form $\ce{A + B <=> C}$ and others have the form $\ce{A + B<=>C + D}$. I'm ...
0
votes
1answer
24 views

What is the difference between a chemical state and just a combination?

I don't think a combination also can be called a "state" i.e. that the chemical state of vapour or solid would be just a combination. When I read Wikipedia about "chemical state" it refers to just a ...
7
votes
2answers
154 views

Significant Figures Interpretation

Please correct me if I’m wrong, but I’ve read that the reason why we use significant figures is to avoid making the result of a calculation more accurate than the starting values prior to the ...
5
votes
2answers
828 views

Basic Understanding of Relative Atomic Mass

I’m currently trying to learn some chemistry and have run into some trouble understanding some of the basics. The confusion stems from a passage in my textbook, so I will list the brief passage and ...
4
votes
1answer
165 views

What is a “lagged bath”?

First question, and this is one I've searched for in vain. In the context of setting up cooling baths, I've come across the term "lagged" bath. I cannot extract what this means from any available ...
2
votes
1answer
57 views

What is a 'Trace Crossing'?

I'm reading about electrodeposition of conductive polymers in a chemistry textbook, and the author mentions 'trace-crossing' in the 'potentiodynamic response'. From the context I can figure out that ...
4
votes
2answers
86 views

Correct nomenclature for reaction types

What is the correct name for a reaction like this? $$ \ce{ 4MnO2 ->[500\ ^\circ \text{C}] 2Mn2O3 + O2 ^}$$ Is it a synthesis, or a Decomposition? I tried to find it out with ...
2
votes
1answer
43 views

Is (S)-3-hydroxypalmitoyl-CoA a hydroxy fatty acyl-CoA?

Is there anything special about (S)-3-hydroxypalmitoyl-CoA comparing to those with different number of carbons, e.g. (S)-3-hydroxyoctanoyl-CoA, (S)-3-hydroxydecanoyl-CoA, (S)-3-hydroxylauroyl-CoA? I ...
6
votes
1answer
125 views

What does it mean when “a gas is dilute in CO₂”?

I'm reading an article about carbon sequestration, and I came across a strange phrase: "The flue gas is dilute in $\ce{CO2}$". I can't quite ascertain its meaning from the context. I think it means ...
1
vote
1answer
384 views

Is “ice point” the same as “freezing point”?

I am using an old book and they almost use both terms interchangeably sometimes. Do they mean the same thing? Similiarly for "steam point" and "boiling point"
4
votes
2answers
4k views

Difference between lab-grade and food-grade purity?

What is the difference in purity betwen lab-grade and food-grade when talking about potentially consumable compounds? As an example let's take ascorbic acid powder: if it's marked as lab-grade, does ...
3
votes
1answer
306 views

What is the correct name for this lab technique [crystallization]

Take a glass rod and rub vigorously the wall of the flask, the substance will crystallize out of the solution. Take a fire polished stirring rod and etch (scratch) the glass of your beaker. The small ...
5
votes
4answers
15k views

What is a neutral atom?

Someone gave me definition of atomic number as follows: The number of electron or proton present in a neutral atom is called atomic number. It is represented by ...
4
votes
2answers
264 views

Should one pronounce “periodic” the same in “periodic acid” and “periodic table”?

In “periodic table”, the adjective is related to the noun period, and comes from Ancient Greek περίοδος through French périodique. In “periodic acid”, it is formed from the prefix per- and iodic (like ...