Baking soda has a pH of 10, lemon juice has a pH of 2. How much less acidic is baking soda ?

Question

Hi, I'm really confused with the question. 

Answer 1

Alex,

 

pH tells you how much free hydrogen ion (H+), which we recognize as acidity, is in a solution with two caveats:

1. Small numbers mean more hydrogen ion and more acidity.
2. A difference of one in pH is means 10 times as much hydrogen ion.

 

So, because lemon juice has a lower pH than baking soda, lemon juice has more acidity than baking soda. (This we know because of caveat #1.)

 

To figure How Much? you need the difference in pH: 10-2 = 8, that is, eight factors of 10 less acid: 10x10x10x10x10x10x10x10 = 10⁸ or a 100 million times less acid. (This we know from caveat #2.)

 

Your tongue won't recognize millions of different acid strengths, but it might recognize a dozen different pH values found in common foods. (Caveat #3: Be careful!)

 

Michael.