Which substances will have a higher hydrogen ion concentration?

The pH Scale

The graphic that you attached is an illustration of the pH scale. 

• Substances that have pH numbers less than 7 are acids. Acids tend to disassociate into `~H^+` ions and negatively charged anions when dissolved in water. The lower the pH number, the stronger the acid.` `

• Pure water has a pH of 7. It is considered neutral. The concentration of `~H^+` ions and `~OH^-` ions in water is equal.

• Substances that have pH numbers greater than 7 are bases. Bases tend to disassociate into positively charged cations and `~OH^-` ions when dissolved in water. The higher the pH number, the stronger the base.

Calculating pH

The pH of a substance is a measure of the concentration of `~H^+` ions.:

   pH = -log[`~H^+` ]

The square brackets around the `~H^+` stand for "the concentration of."

Calculating [`~H^+` ]

[`~H^+` ] ions can be calculated by rearranging the above formula to:

   [`~H^+` ] = `~10^-^p^H`

The [`~H^+` ] for battery acid (pH 1) would be:

    `~10^-^1` = 0.1 M

The [`~H^+` ] for lye (pH 13) would be:

   `~10^-^13` = 1 x `~10^-^13` M

Therefore, the lower a substance's pH, the higher the [`~H^+` ].

The order of substances from highest to lowest [`~H^+` ] is: battery acid, lemon juice, wine, normal rain, distilled water, baking soda, soft soap, ammonia, lye.