Quick Answer: Why Can PH Be Negative?

What substance has a pH of 0?

The pH scaleIncreasing pH (Decreasing Acidity)Substances0 (most acidic)Hydrochloric acid (HCl)1Stomach acid2Lemon juice3Cola, beer, vinegar15 more rows.

How is pH calculated?

Calculating_pHandpOH. To calculate the pH of an aqueous solution you need to know the concentration of the hydronium ion in moles per liter (molarity). The pH is then calculated using the expression: pH = – log [H3O+].

What is the pH of pure water?

7The pH of pure water is 7, the negative logarithm of 1 X 10-7. A neutral solution is one that is neither acidic nor basic. The hydrogen ion concentration equals the hydroxide ion concentration, and both equal 1 X 10-7 M.

Can pH have negative value?

Thus, measured pH values will lie mostly in the range 0 to 14, though negative pH values and values above 14 are entirely possible. Since pH is a logarithmic scale, a difference of one pH unit is equivalent to a tenfold difference in hydrogen ion concentration.

Why is pH a negative log?

Since the molar concentration of hydrogen in aqueous solution is a very small number like 10^-7, its logarithm is negative and its negative is positive. For convenience sake, the unwieldy molar concentrations are converted to simple numbers by taking negative of their logarithms.

Why pH is not more than 14?

pH = 14 corresponds to an aqueous solution of a strong base of molarity 1. By the same definition, pH = 0 corresponds to an aqueous solution of a strong acid or molarity 1. Higher concentrations result in pH > 14 for strong bases and pH < 0 for strong acids. ... So, that's why, the pH is not more than 14.

Why is a pH of 7 neutral?

Ions are just atoms that have an electric charge on them, so H+ is a hydrogen atom with charge of 1. Even in pure water ions tend to form due to random processes (producing some H+ and OH- ions). The amount of H+ that is made in pure water is about equal to a pH of 7. That’s why 7 is neutral.

What has a pH of 13?

What does it mean for a solution to be acidic or basic (alkaline)?pH ValueH+ Concentration Relative to Pure WaterExample110.000 1ammonia solution120.000 01soapy water130.000 001bleach, oven cleaner140.000 000 1liquid drain cleaner11 more rows

What does negative pH mean?

In practice, any acid that yields a concentration of hydrogen ions with a molarity greater than 1 will be calculated to have a negative pH. … To further complicate the situation, the activity or effective concentration of hydrogen ions in a concentrated strong acid is higher than the actual concentration.

Can the pH of a solution be zero or negative?

pH is defined as the logarithm of reciprocal of concentration of hydrogen in the solution. It implies, pH can not be negative whether it is an acid or a base. The scale range of pH is 0–14, where pH 7 is neither a base nor an acid, that is pure water.

Is pH above 14 possible?

It describes how many hydrogen ions (protons) are present in a solution: the higher the pH, the lower the hydrogen ion concentration, and vice versa. But the scale does not have fixed limits, so it is indeed possible to have a pH above 14 or below zero.

What pH is rain water?

between 5.0 and 5.5Normal, clean rain has a pH value of between 5.0 and 5.5, which is slightly acidic. However, when rain combines with sulfur dioxide or nitrogen oxides—produced from power plants and automobiles—the rain becomes much more acidic. Typical acid rain has a pH value of 4.0.