Question

the pH scale is a logarithmic scale. this mean that the difference between 2 pH units is really a factor of 10. with this is mind:
how may times more acidic is a solution whose pH = 1 compared to a solution whose pH = 5?
wouldn't the answer be 20?
because 5-1 = 4
and since the difference b/w 2 pH units is a factor of 10..then 2*10 = 20?
i'm not sure if i'm correct

how many times more basic is a solution whose pH = 12 compared to a solution whose pH = 10?
this one i'm kind of lost in...

Answer 1

You were correct when you said there is a factor of 10 difference between pH = 1 and pH = 2. However, each additional step in value gets the same treatment: a factor of 100 between 1 and 3, a factor of 1,000 between 1 and 4, and a factor of 10,000 between 1 and 5.

Simply, if you are dealing with whole number pH values, take the difference and add that many zeroes after "1" to get the factor change.

So, pH = 12 from pH = 10 is a 100-fold change in the basic direction.