0.20 g of sodium hydroxide (NaOH) pellets are dissolved in water to make 4.5 L of solution. What is the pH of this solution? Express the pH numerically to two decimal places.

A certain weak acid, HA, has a Ka value of 5.5×10−7.
Part A
Calculate the percent ionization of HA in a 0.10 M solution.
Express your answer to two significant figures and include the appropriate units.

Calculate the percent ionization of HA in a 0.010 M solution.
Express your answer to two significant figures, and include the appropriate units.

[H+]= 1.1×10−9 M .
Express the molarity to two significant digits.