X and Y are solutions of two different acids - Edexcel - GCSE Chemistry Combined Science - Question 6 - 2019 - Paper 1

The concentration of hydrogen ions in solution X is ten times higher than that in solution Y. This is due to the difference in pH values; the pH scale is logarithmic, meaning a difference of 1 pH unit corresponds to a tenfold difference in hydrogen ion concentration. Hence, if solution X has a pH of 3.40 and solution Y has a pH of 4.40, we can deduce:

For solution X: $[H^+] = 10^{-3.40}$

For solution Y: $[H^+] = 10^{-4.40}$

The ratio of the hydrogen ion concentrations is: $\frac{10^{-3.40}}{10^{-4.40}} = 10^{(4.40 - 3.40)} = 10^1 = 10$

Thus, hydrogen ion concentration in solution X is ten times higher compared to solution Y.