Calculating pH of Strong Acids and Bases

Question 1

What is the equation for calculating pH of an acid?

Answer 1

pH = -log[H+] [H+] is concentration of H+ ions

Question 2

Strong Acids Notes :

Answer 2

• Completely dissociate
• Concentration of H+ ions in a monoprotonic strong acid is the same as the concentration of the acid
• In HCL and HNO3, [H+] is the same as the original concentration of the acid

Eg. 0.1 moldm^-3 of HCl, pH is -log[0.1] = 1

Question 3

What is the equation for finding [H+] from pH?

Answer 3

[H+] = 10^-pH

Question 4

How do you calculate the pH of a strong base?

Answer 4

• Find [H+]
• Into Kw = [H+] [OH-]
• Rearrange for [H+]
• Into pH = -log[H+]