December 04, 2022, 07:25:47 AM
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Topic: Some questions regarding pH, bases and acids  (Read 112 times)

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Offline Shaderxd

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Some questions regarding pH, bases and acids
« on: November 30, 2022, 05:22:11 PM »
I have an exam coming up on this topic and have a few questions.
Okay so first of all when do I use -log10 vs just -log because there are some questions that involve -log10 and they don't even use the Molarity they just come up with the number of moles and then do it -log only. What is -log10 basically

How do I calculate mass vs calculating concentrations ?

When is it necessary to convert grams to litres regarding these questions?

In Va x Ma/Na = Vb x Mb/Nb how do I know when Na and Nb are 1 and 1 or 1 and 2
That's all I need to know thanks

Offline Borek

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Re: Some questions regarding pH, bases and acids
« Reply #1 on: December 01, 2022, 03:58:56 AM »
I have an exam coming up on this topic and have a few questions.I have an exam coming up on this topic and have a few questions.
(...)
That's all I need to know thanks

These questions are almost impossible to answer, they are way too ambiguous and make no sense without context - which suggests these are not "the only things" you don't know. It is rather that you don't grasp underlying concepts and these things are just a tip of an iceberg :(

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Okay so first of all when do I use -log10 vs just -log because there are some questions that involve -log10 and they don't even use the Molarity they just come up with the number of moles and then do it -log only. What is -log10 basically

If it is all about pH can be it is just a lousy used notation and it is log base 10 all the time. Hard to say without seeing problems in which these logarithms were used. log10 means logarithm base 10, log can mean natural logarithm or logarithm base 10, there is no single convention.

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How do I calculate mass vs calculating concentrations ?

No way to answer that, you could as well ask "how do I calculate length and how do I calculate weight" and it would make about as much sense.

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When is it necessary to convert grams to litres regarding these questions?

When you need volume and you have mass, you try to convert mass to volume. Again, this question doesn't make much sense without context.

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In Va x Ma/Na = Vb x Mb/Nb how do I know when Na and Nb are 1 and 1 or 1 and 2

Sigh, how do we know what these symbols mean? They are not established, just because your lecturer used them doesn't mean everyone knows what they mean. If I were to guess I would assume Na and Nb are stoichiometric coefficients or numbers of dissociable protons in reacting substances.
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