Reactions between Metals and Acids

This activity tests a student's ability to understand the reactions between Metals and Acids.

 

First off, when an acid reacts with a metal, the acid will react with the metal to produce the metal salt of that acid; at the same time, it will produce hydrogen gas.

 

What does that look like?  The general path of these metal/acid reactions is:

 

Acid + Metal  Salt + Hydrogen

 

(NB: note that the word 'salt' here refers to a metal salt, i.e. a compound of the metal which has been formed through reaction with an acid, e.g. zinc chloride, potassium nitrate and iron sulfate are all metal salts).

 

Here are two examples of reactions of different metals with dilute acids:

 

Zinc + Sulfuric Acid  →  Zinc Sulfate + Hydrogen
Magnesium + Hydrochloric Acid  →  Magnesium Chloride + Hydrogen  

 

So where did the 'sulfate' or 'chloride' come from?  It might help to use compound names for these acids - after all, they are all compounds of hydrogen in solution.  Try this:

  HYDROCHLORIC ACID  =  HYDROGEN CHLORIDE SULFURIC ACID  =  HYDROGEN SULFATE NITRIC ACID  = HYDROGEN NITRATE  

Now look back at those two word equations above - can you see where the zinc sulfate and the magnesium chloride have come from?   Let's check out one more:

 

Copper + Nitric Acid  →  Copper Nitrate + Hydrogen  could be re-written as:

 

Copper + Hydrogen nitrate  →  Copper nitrate + Hydrogen

 

In all of the above reactions, the metal has taken the place of the hydrogen in the acid and formed a metal salt.  It's a type of displacement reaction.