Class 9 - Chemistry - Formulae of Simple Compounds - Atoms and Molecules #class9Chemistry #class9Science #eduvictors #cbseClass9

Class 9 - Chemistry - Formulae of Simple Compounds - Atoms and Molecules

Q1: What is a chemical formula?

Answer: The chemical formula of a compound is a symbolic representation of its composition.

Q2: Write the chemical formula for the following compounds. Also identify the ions formed.

➀ Hydrogen Chloride

➁ Hydrogen Sulphide

➂ Carbon Tetrachloride

➃ Magnesium Bromide

Answer: 

➀ Hydrogen Chloride

Ions formed are H⁺ (cation) and Cl⁻ (anion)

➁ Hydrogen Sulphide

Ions formed are H⁺ (cation) and S²⁻ (anion)

➂ Carbon Tetrachloride

Ions formed are C⁴⁺ (cation) and Cl⁻ (anion)

Note: As such no charge formation takes place. For simplicity, we show charges here.

➃ Magnesium Bromide

Ions formed are M²⁺ (cation) and Cl⁻ (anion)

Q3: Write the chemical formula of:

➀ Sodium Carbonate

➁ Ammonium Chloride

➂ In a molecule of sodium carbonate, how many sodium atoms are there?

➃ In a molecule of ammonium chloride, how many chloride ions are there?

Answer:

➀ Sodium Carbonate

➁ Ammonium Chloride

➂ In a molecule of sodium carbonate, there are 2 sodium atoms.

➃ In a molecule of ammonium chloride, there is 1 chloride ion.

👉See Also:

How to learn naming Chemical Formula
Ch 3 - Atoms and Molecules
Ch 3 - Atoms and Molecules (Worksheet)
Ch3 - Atoms and Molecules (MCQs) 
Ch 3 - Atoms, Molecules and Ions (Study Points)
Ch 3 - Atoms and Molecules (MCQs-2)
Ch 3 - Atoms and Molecules - Atomicity of Elements (Worksheet)
All about Names of the Chemical Elements
Ch 3 - Atoms and Molecules (Important Definitions)