Question

If a solution has a pH of 7, this means that

A) this is a solution of pure water, and the concentration of H+ ions in the water is 10-7 M.
B) this is a solution of pure water, and the concentration of H+ ions equals the concentration of OH- ions in
the water.
C) this is a solution of pure water.
D) the concentration of H+ ions in the water equals the concentration of OH- ions in the water.
E) there are no H+ ions in the water."

Answer 1

A solution with a pH of 7 is neutral, indicating that the concentrations of H+ and OH- are equal, each being 1.0 x 10^-7M. This condition often applies to pure water but isn't exclusive to it, as any neutral solution will have these concentrations.

Step-by-step explanation:

If a solution has a pH of 7, this means that the concentration of H+ ions equals the concentration of OH- ions in the water. The hydrogen ion concentration is 1.0 x 10-7M, which signifies a neutral pH. This can occur in pure water, but it's not limited to pure water; any solution with these equal concentrations, regardless of its composition, is considered neutral.

The concept of pH is pivotal in chemistry as it is a measure of the acidity or alkalinity of a solution. Neutral solutions have pH values of exactly 7.00, which applies to pure water at 25 °C.