Advertisements
Advertisements
Question
Name the elements water is made of. What are the valencies of these elements ? Work out the chemical
formula for water.
Advertisements
Solution
Water (H2O) is made of Hydrogen and Oxygen.
Valency of Hydrogen is 1, and valency of Oxygen is 2.
Valency of one Hydrogen atom = 1
Valency of one Oxygen atom = 2
Therefore, to balance the valency of Oxygen atom, 2 atoms of Hydrogen atoms are required.
Hence, 2 atoms of Hydrogen will combine with 1 atom of Oxygen to form one molecule of water with the chemical formula H2O.
APPEARS IN
RELATED QUESTIONS
What is meant by the term chemical formula?
The radius of an oxygen atom is 0.073 nm. What does the symbol ‘nm’ represent ?
If the valency of hydrogen is 1 and that of nitrogen is 3, work out the formula for ammonia.
The formula of carbonate of a metal M is M2CO3.
What will be the formula of its phosphate ?
Write chemical formula of the sulphate of Aluminium, Ammonium and Zinc.
Identify the following substance:
An alkaline gas A which gives dense white fumes with hydrogen chloride.
Write the formula of the following compound:
Calcium chloride
Write the formula of the following compound:
Magnesium sulphate
Write the formula of the following compound:
Lead [II] nitrate
Play a game for writing formula.
Example 1: Make placards with symbols and valencies of the elements separately. Each student should hold two placards, one with the symbol in the right hand and the other with the valency in the left hand. Keeping the symbols in place, students should criss-cross their valencies to form the formula of a compound.
