Question

How much more [H+] does lemon juice (pH 2) have compared with pure water (pH 7)? Remember that each pH unit represents a 10 fold change in the [H+].

Answer 1

Answer:

$10^5 \\or\\100,000$

Explanation:

As we know that the formula for pH is

$pH = -[log H+]$

It is also given in the question that one pH unit represents the 10 fold change in the concentration of hydrogen ion.

Now for lemon juice whose pH is 2, hydrogen ion concentration is equal to

$10^-2\\= \frac{1}{100}$

And for pure water whose pH is $7$, hydrogen ion concentration is equal to

$10^ -7\\= \frac{1}{10000000}$

Thus, the H+ ion concentration in lemon juice is $10^5$ times greater than the pure water.