Question

Use Mendeleev's Periodic Table to predict the formulae for the oxides of the following elements:
K, C. AI. Si, Ba.

Answer 1

K is in group 1. Therefore, the oxide will be K2O.

C is in group 4. Therefore, the oxide will be CO2.

Al is in group 3. Therefore, the oxide will be Al2O3.

Si is in group 4. Therefore, the oxide will be SiO2.

Ba is in group 2. Therefore, the oxide will be BaO.

Answer 2

*We can predict the formula for the oxide of given element using Mendeleev's periodic table.

*Here valency of given element can be  calculated if we know their group in Mendeleev's periodic table.And hence the formula of oxide can be calculated.

• Potassium(k) belongs to group IA .So its valency is 1 and formula of oxide is K₂O.
• Carbon(C) belongs to  group IVA and  its valency is 4.Formula of oxide is C₂O₄ or CO₂.
• Aluminium(Al) belongs to group IIIA and its valency is 3.Formula of oxide is Al₂O₃.
• Silicon(Si) belongs to group IVA and its valency is 4.Formula of oxide is Si₂O₄ or SiO₂.

• Barium (Ba) belongs to group IIA and valency is 2.So formula of oxide is Ba₂O or BaO.