Mastering Chemical Formulas for Ionic Compounds

The video tutorial explains how to write chemical formulas for compounds like Sodium Oxide, Aluminium Chloride, Sodium Sulphide, and Magnesium Hydroxide. It covers the concept of valency and the method of cross-multiplying valencies to balance charges and derive the correct chemical formulas.

What is the first step in writing the chemical formula for a compound?

• Find the boiling point

• Determine the melting point

• Calculate the molecular weight

• Identify the elements involved

How do you determine the chemical formula for Sodium Oxide?

• By cross-multiplying the valencies of Sodium and Oxygen

• By adding the atomic numbers

• By subtracting the valencies

• By using the periodic table

What is the chemical formula for Sodium Oxide?

• NaO

• Na2O

• NaO2

• Na2O2

What are the valencies of Aluminium and Chlorine in Aluminium Chloride?

• 3 and 1

• 1 and 2

• 2 and 1

• 1 and 3

What is the chemical formula for Aluminium Chloride?

• Al2Cl3

• AlCl3

• AlCl2

• AlCl

How do you derive the formula for Sodium Sulphide?

• By using the molecular weight

• By using the atomic numbers

• By adding the valencies

• By cross-multiplying the valencies of Sodium and Sulphur

What is the chemical formula for Sodium Sulphide?

• Na2S2

• Na2S

• NaS

• NaS2

How is the formula for Magnesium Hydroxide written?

• MgOH

• Mg(OH)2

• Mg2OH

• MgO2H