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Questions tagged [definitions]

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3 votes
2 answers
186 views

Does "concentration gradient" refer to the amount of all solutes, or a specific solute moving across a membrane?

I'm struggling with something that seems really simple, and I think it's because I'm stuck on the definition of concentration gradients. If you have a solution with a moderate concentration of ...
Riles's user avatar
  • 49
-1 votes
2 answers
73 views

Is methylenecyclopropane a cycloalkene?

Are all compounds with a ring and double bonds considered cycloalkenes? Can the double bond be outside the ring in a cycloalkene (example: methylenecyclopropane)
EagerToLearn's user avatar
7 votes
1 answer
710 views

Uncertainty when beaker goes by 50s

I am helping my daughter do her chemistry homework and am stumped by this one. I have a beaker that seems to count by 50s. That makes uncertainty calculations awkward. What is the “next unit down”? ...
Vaccano's user avatar
  • 231
1 vote
1 answer
50 views

What is the relation between cross-section and spectral line intensity?

I was told by my supervisor that there is a relation between these two and he talked about a coefficient connecting the two of them. I am currently brushing up a lot of chemistry as I'm a physics ...
Benvz's user avatar
  • 53
5 votes
2 answers
131 views

What words can I use to differentiate between cases where two atoms are of the same element versus when two atoms are of different elements?

I am writing my thesis, and usually I'm quite good with picking the right words for specific phenomena, yet I am having trouble finding the right words for this specific circumstance. I am trying to ...
thelocalsage's user avatar
  • 1,247
1 vote
1 answer
84 views

Redefinition of mole 2019

The mole was redefined in 2019 to $6.02214076\times 10^{23}$ elementary entities. I've learnt that this means that the mass of one mole of Carbon 12 is now no longer exactly 12g. However isn't ...
Stark's user avatar
  • 95
6 votes
1 answer
391 views

Is it appropriate to call an element an amphoteric substance?

In most of Japanese high-school textbook it is written that Al,Zn,Sn and Pb are amphoteric element(in Japanese 両性元素)because they react both with strong acid and base. For example Al reacts like below. ...
satoru kurita's user avatar
0 votes
1 answer
371 views

Are corrosive and reactive synonymous?

This answer on a question regarding whether water is corrosive in pure form, the author implies that "reactive" and "corrosive" are the same thing (at least with water.) "...
Melanie Shebel's user avatar
0 votes
0 answers
19 views

Is the graphene sheet in graphite considered molecule? What is considered molecule? [duplicate]

molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance. -...
Dick A's user avatar
  • 1
0 votes
0 answers
88 views

Definition of an internal reference

Warning: extreme pedantry. I am performing Gutmann-Beckett experiments, basically utilizing an NMR-tube with my sample and a 31P-lewis base (e.g. triethylphosphine oxide) inside another one with a ...
Katjuscha's user avatar
0 votes
0 answers
40 views

What is meant by "charge separation" for resonance structures? [duplicate]

I'm confused about the definition of "charge separation" in the context of resonance structures. One of the rules of stability of resonance structure is "the structure with least ...
Feraminecarts's user avatar
-2 votes
2 answers
873 views

Isn't hydrogen chloride a salt, because it is an ionic compound? [closed]

So I just learned in chemistry that salts are ionic compounds. Shouldn't, $\ce{H+Cl-}$ be a salt since hydrogen ion has positive charge and chloride ion has negative charge? If $\ce{HCl}$ is a salt ...
parth singla's user avatar
2 votes
0 answers
147 views

Error in the IUPAC Gold Book definitions of exergonic, endergonic, exothermic and endothermic?

All definitions in the IUPAC Gold Book refer to standard values: exergonic reaction (exoergic reaction) [link] This expression is often applied to a reaction for which the overall standard Gibbs ...
The Quark's user avatar
  • 597