IB DP Chemistry: HL复习笔记8.2.2 pH & [H⁺]

• 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