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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:
K2SO4
Give the name of the element present in the following compound:
Hydrogen bromide
Give the name of the element present in the following compound:
Baking powder
Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.
State the term.
The number of atoms present in a molecule of an element _________
Define: Atomic weight :
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 ?
An element A forms an oxide A2O5.
What is the valency of element A ?
Calculate the mass of 3.011 × 1024 atoms of carbon.
Correct the following statement:
A molecule of sulphur is monoatomic.
State true of false. If false, give the correct statement.
NaCl represents one molecule of sodium chloride.
Which of the following is a triatomic molecule?
The Atomicity of phosphorous is ______
Give any two examples for heterodiatomic molecules.
Derive the relationship between Relative molecular mass and Vapour density.
Write any two classifications of a molecule.
