Chemical reaction equations vs balancing equations?

[TJ McCaustland]

Hi, so I know how to balance chemical equations, (instead of H2O it's 2H2O) But what exactly differs a reaction equation from abalancing equation?

[studiot]

Can you give some examples?

 

I would say that perhaps you mean the difference is that sometimes the equation gives the conditions of the reactants and products, for example in solution, where the solvent does not participate in the reaction but needs to be present for the reaction to proceed.

 

for example

 

[math]N{a_2}C{O_3}(aq) + CaC{l_2}(s) \to CaC{O_3} \downarrow + 2NaCl(aq)[/math]

But what happens if you just mix solid sodium carbonate and solid calcium chloride together?

Both are white powders.

 

Note 'balancing' a chemical equation only makes sense if there is a chemical reaction and there are some products different from the reactants.

In the above you could say that the chemical reaction consists of dissolving calcium chloride in a solution of calcium carbonate and that calcium carbonate is precipitated from the solution, without quantities as I have done.

 

Or you could just say the chemical reaction in words

 

eg a more general one

 

Acid + Base = Salt plus Water

Edited October 29, 2015 by studiot

[TJ McCaustland]

Well an example of a reactant of fuming nitric acid coming in contact with another reactant that would produce a hypergolic reaction. Is there a specific mathematical formula for determining the outcome necessarily when you mix two elements that react hypergolically? Or two stable elements such as O₃+S₂ --> 2SO₃? Or is it simply found out by experimenting?

Edited October 30, 2015 by TJ McCaustland

[studiot]

What if they don't react?

Are they still reactants?

 

Chemistry is not a branch of Mathematics (nor Mathematics a branch of chemistry), but both are useful to the other.

 

You need chemical knowledge as well as the mathematical kind.

 

In the case of sulphur and oxygen you should look up Activation Energy.

 

https://www.google.co.uk/search?hl=en-GB&source=hp&biw=&bih=&q=activation+energy&gbv=2&oq=Activation+Energy&gs_l=heirloom-hp.1.0.0i131j0l9.1031.4672.0.6938.17.13.0.3.3.0.203.1423.0j8j1.9.0....0...1ac.1.34.heirloom-hp..5.12.1549.fcOjfyfhZs4

[TJ McCaustland]

Did I use the abbreviation for sulphur...... I meant Silicon....

Well what I was asking was how do you determine the outcome of mixing two elements? Must you do it in an experiment, or can you figure it on paper?

[studiot]

Did I use the abbreviation for sulphur...... I meant Silicon....

Well what I was asking was how do you determine the outcome of mixing two elements? Must you do it in an experiment, or can you figure it on paper?

 

 

Did you mean silicon?

Did you also mean silicon trioxide?

 

Chemistry is all about answering questions like these, as well as your own in the quotes.

 

But it is much more complicated that asking how much does 1 litre of oil weigh, which can be obtained from a simple arithmetical formula.

 

First you need to know some chemistry.

 

The law of definite proportions.

 

Pure substances (including elements) always combine in the same or definite proportions.

 

So as a first approximation we can say X amount of sulphur will combine with Y amount of oxygen to form sulphur dioxide; the ratio X/Y, is always the same.

 

But will silicon or sulphur form trioxide or dioxide?

 

Well secondly you need to know some chemistry, specifically elementary valency.

 

https://www.google.co.uk/search?hl=en-GB&source=hp&biw=&bih=&q=valency&gbv=2&oq=valency&gs_l=heirloom-hp.3..0i131j0l9.1656.4172.0.6047.7.7.0.0.0.0.234.1000.0j5j1.6.0....0...1ac.1.34.heirloom-hp..1.6.1000.KgauRuffOzE

 

(Did you look up my last reference?)

 

This will help you form proposed chemical reactions, according to the rules of valency.

 

Having got your stoichiometery (proportions) correct you can ask

 

Is the reaction possible?

 

To address this question you need to know some more chemistry, chemical thermodynamics or chemical energetics.

 

The reaction could proceed if it releases energy in doing so.

But some proposed reaction, correct on valency rules, cannot proceed without energy being added.

 

So you have to heat up the reagents.

 

Even if the reaction is energetically favourable, it may proceed rapidly or slowly or even so slowly as to be be negligable.

 

To understand this you need to know some more chemistry.

 

Rates of reaction are covered in chemical kinetics, but this mathematics may be offset by passivation or other interfering layers.

 

So hopefully you can begin to see why chemistry is a very large and rich subject.

 

[TJ McCaustland]

Thanks man. +1 to all your posts.

[studiot]

These are good question so keep asking them.