can someone give a simple explanation of what causes PH to vary?

Question

Is it something to do with the number of Hydorgen Ions?

Like the more H ions, the more acidic?

Answer 1

Yes!!!
The more hydrogen ions in a given volume the LOWER the pH.
The hydrogen ions can be varied by adding/subtracting hydroxide ions (OH-).
The more hydroxide ions the greater the pH.
The value of pH ranges from 0 (zero) totally acidic to 14 totally alkaline. Water pH 7 is neutrality.
These values are calculable but for everyday purposes are arbitrary.

Answer 2

The concentration of hydrogen ions is commonly expressed in terms of the pH scale. Low pH corresponds to high hydrogen ion concentration and vice versa. A substance that when added to water increases the concentration of hydrogen ions(lowers the pH) is called an acid. A substance that reduces the concentration of hydrogen ions(raises the pH) is called a base. 0-6 pH is an acid, 8-14 is a base, and 7 is neutral (pure water)

Answer 3

The addition/increase of H+ ions will cause the pH to DROP (become more acidic. The removal of OH- ions may also lower the pH

The addition of OH- ions will RAISE the pH (make it more basic/alkaline). The removal of H+ will also raise the pH.

Answer 4

That is exactly right.

The higher the concentration of Hydrogen ions the lower the pH.

pH = - log [H+]

Where [H+] = H+ concentration

so if you have 10 mols / dm3 of H+ the pH is -1

log 10 = 1 therefore - log 10 = -1

And yes you can get a solution that acidic.

Oh a dm3 is equivalent to 1 litre and mols is a chemical constant = to avagadros number which is 6.02214199 × 10^23.

So it is a lot of hydrogen ions

That may be a little indepth but i hope i explained everything

Answer 5

The full name for the unit pH gives the game away. Proton hydrogen. The level of hydrogen protons alters the acidity / alkalinity of the solution.