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प्रश्न
State the law of conservation of mass. Give one example to illustrate this law.
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उत्तर
Law of conservation of mass states that the matter is neither created nor destroyed in a chemical reaction.
It was proposed by Antoine Lavoisier in 1774. It means that in a chemical reaction, the total mass of products (new substances that are formed in a chemical reaction) is equal to the total mass of reactants (substances which combine together in a chemical reaction).
Law of conservation of mass can be illustrated by the following chemical reaction where 100 grams of calcium carbonate decomposes to produce 56 grams of calcium oxide and 44 grams of carbon dioxide.
Calcium carbone → Calcium oxide + Carbon dioxide
100 gm 56 gm 44gm
Here,
Mass of reactant (calcium carbonate) = 100gm
Mass of products (calcium oxide & carbon dioxide) = 56gm + 44gm = 100gm
Since, the mass of reactant (100gm) is equal to the mass of the products (100gm), there is no change in mass in this chemical reaction. Therefore, this example illustrates the law of conservation of mass.
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संबंधित प्रश्न
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of acetic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium acetate. Show that these observations are in agreement with the law of conservation of mass.
Sodium carbonate + acetic acid → sodium acetate + carbon dioxide + water
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State the main points of Landolt’s experiment for experimental evidence of the law.
Complete the statement by filling the blank with the correct word given below.
The law of conservation of mass is strictly valid if mass and _________ are considered together.
Match the following.
| Law of conservation of mass | Sir William Crookes |
| Law of constant proportion | James Chadwick |
| Cathode rays | Joseph Proust |
| Anode rays | Lavoisier |
| Neutrons | Goldstein |
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