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प्रश्न
Why are the symbols and formulae of substances important?
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उत्तर
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].
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संबंधित प्रश्न
Write down the name of a compound represented by the following formula:
CaCl2
Give the name of the element present in the following compound:
Quick lime
Give the name of the element present in the following compound:
Baking powder
Give the name of the element present in the following compound:
Potassium sulphate
Define: Atomic number
In what form does oxygen gas occur in nature ?
In what form do noble gases occur in nature?
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 ?
What are (i) ionic compounds, and (ii) molecular compounds ? Give two examples of each type of compounds.
The cation of an element has :
Molecular compounds are usually formed by the combination between :
Give one example of a polyatomic molecule.
Give a reason why –
Ozone is considered triatomic, but phosphorus a tetratomic molecule.
State the atomicity of the following:
Oxygen
State the atomicity of the following:
Argon
Classify the following molecules as the molecules of element or compound
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Which of the following is a triatomic molecule?
Derive the relationship between Relative molecular mass and Vapour density.
