Advertisements
Advertisements
प्रश्न
What is a chemical formula? What is the significance of a formula?give an example to illustrate?
Advertisements
उत्तर
The chemical formula is used to describe the types of atoms and its number in an element or compound.
Significance- Chemical formula is very important when trying to find information about chemical compounds because they tell us about the elements present and the number of atoms in that compound.
Example - Salt - NaCl, ethanol C2H6O because the molecule of ethanol contains two Carbon, 6 Hydrogen and 1 Oxygen atom.
APPEARS IN
संबंधित प्रश्न
Write the chemical formula of the Magnesium chloride.
Fill the following blanks with suitable words :
In a chemical reaction, the sum of the masses of the reactants and the products remains unchanged. This is called ....................
What is the difference between 2H and H2 ?
Write down the formulae for the following compounds :
Calcium oxide
Name the elements water is made of. What are the valencies of these elements ? Work out the chemical
formula for water.
Name the following compounds. Also write the symbols/formulae of the ions present in them :
- CuSO4
- (NH4)2SO4
- Na2O
- Na2CO3
- CaCl2
An element Y has a valency of 4. Write the formula for its :
- chloride
- oxide
- sulphate
- carbonate
- nitrate
Identify the following substance:
A brown gas D with the irritating smell.
Name the element in the compound and give the formula of the following compound:
Acetic acid
Write the formula of the following compound:
Sodium carbonate
Write the formula of the following compound:
Sodium sulphate
Write the formula of the following compound:
Sodium bisulphite
Write the formula of the following compound:
Calcium hydroxide
Write the formula of the following compound:
Iron [III] hydroxide
Define the term Relative molecular mass. State why indirect methods are utilised to determine the absolute mass of an atom. Explain in brief the indirect method used.
State of the following formula of a compound is incorrect. Incorrectly write the correct formula.
NaZnO2
State of the following formula of a compound is incorrect. Incorrectly write the correct formula.
NaO
Find the valency of the element which is underlined in the following formula.
- NaCl
- CO2
- Al (PO4)
- Ba (NO3)2
- CaCl2
Give the chemical formulae for the following compounds and compute the ratio by mass of the combining elements in each one of them. (You may use appendix-III).
- Ammonia
- Carbon monoxide
- (Hydrogen chloride
- Aluminium fluoride
- Magnesium sulphide
