Counting Matter – Maharashtra Board Class 9 Solutions for Science and Technology (English Medium)
AlgebraGeometryScience and TechnologyHindi
Solution 1:
- Matter is neither gained nor lost in a chemical reaction.
- In a compound, the constitute elements are always present in a definite proportion by weight.
- Two or more elements combine to form compound.
- The combining capacity of an element is known as its valency.
Solution 2:
- 56
- 4.456 × 1024
- 414.4
- 1.075 × 1024
- 9.29 × 10-23
- 2.0
- 111.5
Solution 3:
Solution 4:
- Molecular mass of sulphuric acid (H2SO4) = Sum of atomic masses of hydrogen, sulphur and oxygen= (Atomic mass of H) × 2 + (Atomic mass of S) × 1 + (Atomic mass of O) × 4= (1 × 2) + (32 × 2) + (16 × 4)= 98 u
Molecular mass of sulphuric acid (H2SO4) = 98 u
- Molecular mass of potassium nitrate (KNO3) = Sum of atomic masses of potassium, nitrogen and oxygen= (Atomic mass of K) × 1 + (Atomic mass of N) × 1 + (Atomic mass of O) × 3= (39 × 1) + (14 × 1) + (16 × 3)
= 101 u
Molecular mass of potassium nitrate (KNO3) = 101 u
- Molecular mass of hydrogen sulphide (H2S) = Sum of atomic masses of hydrogen and sulphur= (Atomic mass of H) × 2 + (Atomic mass of S) × 1= (1 × 2) + (32 × 1)
= 34 u
Molecular mass of hydrogen sulphide (H2S) = 34 u
- Molecular mass of carbon dioxide (CO2) = Sum of atomic masses of carbon and oxygen= (Atomic mass of C) × 1 + (Atomic mass of O) × 2= (12 × 1) + (16 × 2)
= 44 u
Molecular mass of carbon dioxide (CO2) = 44 u