Lesson Worksheet: Calculating pH Chemistry

Start Practising

In this worksheet, we will practice calculating the pH of a solution and describing the ion-product constant of water.

Q1:

At a temperature of 50∘C, the value of 𝐾 is 5.476×10.

What is the pH of water at this temperature? Give your answer to 1 decimal place.

What is the pOH of water at this temperature? Give your answer to 1 decimal place.

At this temperature, is water acidic, basic, or neutral?

  • ABasic
  • BAcidic
  • CNeutral

Q2:

A solution at 25∘C has an [OH]– of 1.26×10 mol/L. Is the solution acidic, basic, or neutral?

  • ABasic
  • BAcidic
  • CNeutral

Q3:

The pH of a solution is measured to be 4.15. What is the concentration of hydronium ions in this solution? Give your answer to 2 decimal places and in units of mol⋅dm−3.

  • A7.08×10 mol⋅dm−3
  • B1.41×10 mol⋅dm−3
  • C1.41×10 mol⋅dm−3
  • D5.99×10 mol⋅dm−3
  • E7.08×10 mol⋅dm−3

Q4:

Which of the following equations can be used to calculate the pH of a solution from the concentration of hydronium ions?

  • ApH=[HO][OH]3+–
  • BpH=logHO−[]3+
  • CpH=log[HO]3+
  • DpH=10[]HO3+
  • EpH=[HO]3+2

Q5:

A solution at 25∘C has a hydroxide ion concentration of 1.26×10 mol⋅dm−3. What is the pH of this solution to one decimal place?

Q6:

A solution at 25∘C has a[HO]3+of 1.86×10 M. What is the pOH of this solution to 2 decimal places?

Q7:

What is the concentration of OH–ions in a solution at 25∘C with a pH of 12.45? Give your answer to 2 decimal places.

  • A2.82×10 mol⋅dm−3
  • B3.55×10 mol⋅dm−3
  • C3.55×10 mol⋅dm−3
  • D2.96×10 mol⋅dm−3
  • E3.55×10 mol⋅dm−3

Q8:

What is the pH of a solution with a [HO]3+of 3.98×10 mol⋅dm−3? Give your answer to 1 decimal place.

Q9:

An aqueous solution at 25∘C has a [H]+ of 2×10 M. What is the value of [OH]– to the nearest whole number?

  • A2×10 M
  • B4×10 M
  • C5×10 M
  • D2×10 M
  • E4×10 M

Q10:

Two water molecules are able to react with other forms to form a hydronium ion and a hydroxide ion. This is known as the self-ionization of water. Using the concentrations of ions produced, it is possible to determine the equilibrium constant for the ionization of water, also known as the ion product constant of water.

Which of the following equations shows the ion product constant of water?

  • A𝐾=[HO]22
  • B𝐾=[HO]+[OH]3+–
  • C𝐾=−[HO][OH]3+–
  • D𝐾=[HO][OH]3+–
  • E𝐾=[HO][OH]3+–

If the value of 𝐾 is 1.006×10, what is the value of [OH]– to 3 decimal places?

  • A1.003×10 mol⋅dm−3
  • B1.012×10 mol⋅dm−3
  • C5.015×10 mol⋅dm−3
  • D1.006×10 mol⋅dm−3
  • E5.030×10 mol⋅dm−3

Practice Means Progress

Boost your grades with free daily practice questions. Download Nagwa Practice today!

scan me!

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.