Question

Give the formulae of the compounds formed from the following sets of elements :

1. calcium and fluorine
2. hydrogen and sulphur
3. nitrogen and hydrogen
4. carbon and chlorine
5. sodium and oxygen
6. carbon and oxygen

Answer 1

1. Compound formed with calcium and fluorine will have the chemical formula CaF₂. (valency of Ca is 2 and that of F is 1)
2. Compound formed with hydrogen and sulphur will have the chemical formula H₂S. (valency of S is 2 and that of H is 1)
3. Compound formed with nitrogen and hydrogen will have the chemical formula NH₃. (valency of N is 3 and that of H is 1)
4. Compound formed with carbon and chlorine will have the chemical formula CCl₄. (valency of C is 4 and that of Cl is 1)
5. Compound formed with sodium and oxygen will have the chemical formula Na₂O. (valency of Na is 1 and that of O is 2)
6. Compound formed with carbon and oxygen will have the chemical formula CO₂. (valency of C is 4 and that of O is 2, divided by the common factor of 2)