SPM Chemistry (KSSM) Paper 1

05 Chemical Bonds
5.1 Formation of Compounds
1 Lesson
5.1.1 Formation of Compounds
5.2 Ionic Bonds
2 Lessons
5.2.1 Formation of Ion
5.2.2 Ionic Bonding
5.3 Covalent Bonds
1 Lesson
5.3.1 Covalent Bonding
5.4 Hydrogen Bonds
5.5 Dative Bonds
5.6 Metallic Bonds
5.7 Ionic and Covalent Compounds
1 Lesson
5.7.1 Properties of Ionic and Covalent Compounds
5.8 Chemical Bonds - Practices (Coming Soon)
06 Acids, Bases and Salts
6.1 The Role of Water in Acidic and Basic Properties
3 Lessons
6.1.1 Acids
6.1.2 Bases and Alkali
6.1.3 The Role of Water in Acidic and Basic Properties
6.2 Meaning of pH and Determination of pH
1 Lesson
6.2.1 Meaning of pH and Determination of pH
6.3 Strength of Acids and Alkalis
1 Lesson
6.3.1 Strength of Acids and Alkalis
6.4 Chemical Properties of Acids and Alkalis
3 Lessons
6.4.1 Chemical Properties of Acids
6.4.2 Chemical Properties of Alkalis
6.4.3 Writing Ionic Equation of The Reaction of Acids and Alkalies
6.5 Concentration of Aqueous Solution
2 Lessons
6.5.1 Concentration of Aqueous Solution
6.5.2 Molarity and Number of Moles
6.6 Standard Solution
2 Lessons
6.6.1 Standard Solution
6.6.2 Dilution
6.7 Neutralisation
2 Lessons
6.7.1 Neutralisation
6.7.2 Acid-Base Titration
6.8 Salts, Crystals and Their Uses in Daily Life
1 Lesson
6.8.1 Introduction to Salts
6.9 Preparation of Salts
4 Lessons
6.9.1 Solubility of Salts, Oxide and Hydroxide
6.9.2 Preparing Salts
6.9.3 Preparing Soluble Salts
6.9.4 Preparing Insoluble Salts
6.10 Action of Heat on Salts
2 Lessons
6.10.1 Identifying Gases
6.10.2 Effect of Heat on Salts
6.11 Qualitative Analysis
3 Lessons
6.11.1 Colour of Salts
6.11.2 Identifying Anions
6.11.3 Identifying Cations
6.12 Acids, Bases and Salts - Practices (Coming Soon)
2 of 3
Previous Revision

6.2.1 Meaning of pH and Determination of pH

SPM Chemistry (KSSM) Paper 1 6.2 Meaning of pH and Determination of pH 6.2.1 Meaning of pH and Determination of pH
Revision Progress
0% Complete

The pH Scale

  1. pH scale is a measure of acidity and alkalinity. Practically, it is numbered between 0 and 14. 
  2. Neutral substance has pH of 7.
  3. A solution of pH less than 7 is acidic The lower the pH, the more acidic the solution or the higher the concentration of H+ ions in the solution.
  4. A solution of pH above 7 is alkaline. The higher the pH, the more alkaline the solution or higher concentration of OH- ions presence in the solution.
  5. The pH of a solution can be measured by using the Universal indicator, pH paper or with a pH-meter.
 
 

Acids / Alkali Indicator

  1. An indicator is a substance or mixture of substances that when added to the solution gives different colours depending on the pH of the solution. Table below shows the colour of indicators in neutral, acidic and alkaline solution.
    Indicator
    colour in acid pH<7
    colour in neutral pH=7
    colour in alkali pH >7
    litmus
    red
    ‘purple’
    blue
    phenolphthalein
    colourless
    colourless
    pink
    methyl orange
    pinky red
    orange about pH 6
    yellow
    methyl red
    red
    orange
    yellow
    bromothymol blue
    yellow
    green
    blue
  2. The best indicator of all is the universal indicator.
  3. It can be used to show not only whether a substance is acidic or alkaline, but also whether it is a strong acid or a weak acid.
 
(Colour of indicator at different pH value)
 
 
(Litmus paper. The colour of litmus is blue in alkali and red in acid)
(Colour of phenolphthalein in alkali)
(Methyl Orange: The colour of mthyl orange in acidic and alkaline solution. Left: Acidic; Right: Alkaline. This image is shared by Rubashkyn in wikipedia)
 
(Methyl Red: left: acidic, middle: neutral, right: alkaline. This image is shared by LHcheM in Wikipedia)
(Bromothymol Blue pH indicator dye in an acidic, neutral, and alkaline solution (left to right).)
(A roll of universal indicator paper. This image is shared by Bordercolliez in wikipedia)
Back to top
Previous Revision
Back to Revision