Advertisements
Advertisements
Question
State the law of conservation of mass. Give one example to illustrate this law.
Advertisements
Solution
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.
APPEARS IN
RELATED QUESTIONS
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
Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?
State the law of conversation of mass.
Fill in the blank:
Matter is anything that has............. and occupies .............
Name the law of chemical combination which was given by Proust.
The law of conservation of mass was given by :
Copper sulphate reacts with sodium hydroxide to form a blue precipitate of copper hydroxide and sodium
sulphate. In an experiment, 15.95 g of copper sulphate reacted with 8.0 g of sodium hydroxide to form
9.75 g of copper hydroxide and 14.2 g of sodium sulphate. Which law of chemical combination is illustrated by this data ? Give reason for your choice.
Potassium chlorate decomposes, on heating, to form potassium chloride and oxygen. When 24.5 g of potassium chlorate is decomposed completely, then 14.9 g of potassium chloride is formed. Calculate the mass of oxygen formed. Which law of chemical combination have you used in solving this problem ?
An ionic compound will be formed by the combination of one of the following pairs of elements. This pair of elements is :
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 |
