• The acidity of an aqueous solution depends on the number of?H⁺?(H₃O⁺) ions in solution
• The?pH is defined as:

• • where [H⁺] is the concentration of H⁺?in mol dm^–3
• The pH scale is a logarithmic scale with base 10
• This means that each value is 10 times the value below it. For example, pH 5 is 10 times more acidic than pH 6.
• pH values are usually given to 2 decimal places
• The relationship between concentration is easily seen on the following table:

pH & [H+] Table

Answer:

The correct option is?C.

• • The total volume after dilution is 1000.0 cm³?so the concentration of H⁺?has been?reduced?by a factor of 100 or 10^-2, which means an increase of 2 pH units
  • The final solution is therefore?pH 3