O Level Chemistry – pH Scale

We have all heard of pH scale, but exactly is that and how is it related to Acids, Alkalis and Salts in O LEVEL CHEMISTRY.

? Scale range from 1 to 14 (theoretically should be 0 to 14)

? Indicates whether a solution is Acidic, Alkaline or Neutral

? The LOWER the pH value, the HIGHER the Concentration of Hydrogen ions (H+) in the solution and the STRONGER the acid

? The HIGHER the pH value, the HIGHER the Concentration of Hydroxide ions (OH-) in the solution and the STRONGER the alkali

Let us now take a look at how pH scale is related to things that we see and hear in our daily life.

(Click Image to have a better view)

Let’s look at several exam-based questions below to check out your understanding of this section on pH Scale.

Quick Check 1:
One mole of each of the following compounds was dissolved in water to make 1 dm3 of solution. Which of the solutions would have the lowest pH?
A. ammonia
B. ethanoic acid
C. sodium chloride
D. sodium hydroxide
E. sulphuric acid

Quick Check 2:
A man suffering from an excess of acid in his stomach has no indigestion tablets. Which substance could he now take to lower this acidity?
A. aspirin (pH 6)
B. bicarboinate of soda (pH8)
C. lemon juice (pH 5)
D. salt water (pH 7)

PS: Do leave your suggested answers in the “Comments Section” directly below this post.

PPS: This post belongs to a series of blogposts that is associated with Secrets of “Acids, Bases & Salts and Qualitative Analysis revelaed”

Related Articles:

• O Level Chemistry – Physical & Chemical Properties of ACIDs
• O Level Chemistry – Physical & Chemical Properties of Alkalis
• O Level Chemistry – Chemical Definition of ACIDs
• O Level Chemistry – Chemical Definition of BASEs
• O Level Chemistry – Types of Oxides