Advertisements
Advertisements
Question
Why are the symbols and formulae of substances important?
Advertisements
Solution
Importance of symbols and Formulae:
Symbols and formulae of substance gives a lot of information like.
1. Types of elements present in the compound. E.g. (H20 is made of two elements hydrogen and oxygen).
2. Number of each kind of atoms in one molecule. E.g. (water has 2 atoms of hydrogen combined with 1 atom of oxygen.)
3. Mass of one molecule of the compound. E.g. [H2O has mass (1 × 2) + 16 = 18 g].
APPEARS IN
RELATED QUESTIONS
Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.
Define: Atomic weight :
What is meant by atomicity ? Explain with two examples.
Write the formulae of the following compounds. Also name the elements present in them.
- Water
- Ammonia
- Methane
- Sulphur dioxide
- Ethanol
In what form do noble gases occur in nature?
What is the difference between the molecule of an element and the molecule of a compound? Give one example of each.
One of the forms of a naturally occurring solid compound P is usually used for making the floors of houses. On adding a few drops of dilute hydrochloric acid to P, brisk effervescence are produced. When 50 g of reactant P was heated strongly, than 22 g of a gas Q and 28 g of a solid R were produced as products. Gas Q is the same which produced brisk effervescence on adding dilute HCl to P. Gas Q is said to cause global warming whereas solid R is used for white-washing.
- What is (i) solid P (ii) gas Q, and (iii) solid R.
- What is the total mass of Q and R obtained from 50 g of P ?
- How does the total mass of Q and R formed compare with the mass of P taken ?
- What conclusion do you get from the comparison of masses of products and reactant ?
- Which law of chemical combination is illustrated by the example given in this problem ?
The cation of an element has :
Calculate the mass of 3.011 × 1024 atoms of carbon.
Give one example of a triatomic molecule
Give one example of a polyatomic molecule.
Give a reason why –
Helium is considered monoatomic, but hydrogen a diatomic molecule.
State the atomicity of the following:
Argon
Which of the following is a triatomic molecule?
If a molecule is made of similar kinds of atoms, then it is called ______ atomic molecule.
Define: Atomicity.
Give any two examples for heterodiatomic molecules.
Derive the relationship between Relative molecular mass and Vapour density.
Which of the following contains maximum number of molecules?
Write any two classifications of a molecule.
