Advertisements
Advertisements
Question
State the law of conservation of mass.
Solution 1
Law of conservation of mass: It states that mass can neither be created nor destroyed in a chemical reaction. During any change (physical or chemical), matter is neither created nor destroyed. However it may change from one form to another.
Requirements: H-shaped tube called Landolt’s tube, Sodium chloride solution, silver nitrate solution, etc.
Procedure: A specially designed H-shaped tube is taken. Sodium chloride solution is taken in one limb of the tube and silver nitrate solution in the other limb as shown in figure.
Both the limbs are now sealed and weighed. Now the tubes is averted so that the solutions can mix up together and react chemically. The reaction takes place and a white precipitate of silver chloride is obtained.
\[\ce{\underset{\text{(silver nitrate)}}{AgNO3}+\underset{\text{(sodium cholride)}}{NaCl}->\underset{\text{(silver chloride)}}{AgCl↓}+\underset{\text{(sodium nitrate)}}{NaNO3}}\]
The tube is weighed again. The mass of the tube is found to be exactly the same as the mass obtained before inverting the tube.
Thus, this experiment clearly verifies the law of conservation of mass.
Solution 2
The law states that during any chemical change, the total mass of the products is equal to the total mass of the reactants.
RELATED QUESTIONS
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?
Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?
State the law of conversation of mass.
When magnesium is burnt in air, there is an increase in mass after the reaction.
What is mass ?
If an object weighs 6 kg on earth. What will be its weight on moon ?
If an object is taken to the moon from the earth what will be its mass ?
Give reason for the following.
Electricity is not considered matter.
Fill in the blank:
Matter is anything that has............. and occupies .............
Name the scientist who gave law of conservation of mass.
Name the law of chemical combination which was given by Proust.
State the law of conservation of mass. Give one example to illustrate this law.
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 :
Complete the statement given below by filling in the blanks with the correct words.
Atoms contain ________ with positively charged ________.
State the main points of Landolt’s experiment for experimental evidence of the law.
Select the correct answer from A, B, C, D & E for the statement given below:
In Landolt’s experiment – the form in which the chemical energy stored up in the reactants __________ is released.
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 |
The chemical symbol for nitrogen gas is
Name the four laws of chemical combinations.
