Question

Hi! how do I figure out chemicalreactions? i don't get it how can i know what will come when i mix two things

example: Mg(s) + `2H^+`(aq) → Mg2+(aq) + H2(g) how can i know that Magnesium will have a charge of 2+ after the reaction and that it will go from (s) --> (aq)?

Answer 1

The point is that you DON'T know...that is the purpose of the experiment....

Explanation:

So you propose the reaction....

`Mg(s) + 2HCl(aq) rarr MgCl_2(aq) + H_2(g)uarr`

Magnesium, `Z=12`, is an ALKALINE EARTH, from Group 2 of the Periodic Table...and, therefore, it has TWO VALENCE electrons. Likewise, sodium is a Group 1 metal …. it has one valence electron, and it loses this upon oxidation....

`Li(s) + HCl(aq) rarr LiCl(aq) + 1/2H_2(g)uarr`

The Group number, gives the number of valence electrons...