pH and pOH Question

Question

1.  What information does the pH of a solution give? 
2.  What equation is used to calculate the pH of a solution? 
3.  What is the pOH equation? How can pOH be determined from pH? 
4.  What are the hydrogen ion and hydroxide ion concentrations in water? What is the pH and pOH of pure water?

Answer 1

1. The pH of a solution tells us how acidic or basic a solution is. Specifically, it tells us how many hydrogen ions [H⁺] are in a solution. A pH < 7 means a solution is acidic, while a pH > 7 is basic.
2. You can calculate the pH of a solution from several related equations. The most common way to think about calculating it is by using the following equation: pH = -log[H⁺].
3. There are several related equations for this concept as well. The general equation is pOH = -log[OH^-]. This allows you to calculate the concentration of hydroxide ions (OH^-) in a solution. pH and pOH are related through this equation: pH + pOH = 14
4. Pure water is defined as neutral, as it has the exact same number of H⁺ and OH^- ions. Think about the transition of 1 molecule of H₂0 into 1 H⁺ and 1 OH^-. Water creates the same number of positive and negative ions. Using the equations above, pH=pOH=7. You can then find that the concentrations of H⁺ and OH^- are both equal to 10^-7 M.