Lemon juice has a ph of about 2.0, compared to a ph of about 1.0 for stomach acid. therefore, the concentration of h+ in stomach acid is than that of lemon juice.

The concentration of h+ in stomach acid is  times more than that of lemon juice.

Explanation:

Basically, pH is a value that rates how acidic or alkaline a solution is on a scale from 0–14. A pH of 7 is considered neutral. Any pH value below 7 is considered acidic and any pH value over 7 is considered alkaline. Acidic solutions have a lower pH, while basic solutions have a higher pH.

On the pH scale, the difference between adjacent numbers represents a tenfold difference in acidity. For instance, a pH of 4 is 10 times more acidic than a pH of 5 and 100 times more acidic than a pH of 6.

Since the lemon juice has a pH of about 2.0 compared to stomach acid with a pH of about 1.0 It means that the the stomach acid is 10 times more acidic than the lemon juice.

pH = -log10[H+]

[H+] = 10^-pH

In Lemon juice;

[H+] = 10^-pH = 10^-2 = 0.01

In stomach acid;

[H+] = 10^-pH = 10^-1 = 0.1

0.1 is 10 times more than 0.01.