Question

How do you find the volume of an irregular object like a rock or sphere in chemistry?

Answer 1

We can find the shape of the irregular object by placing it in the water and then noting the initial and final volume of the water. We can call this method the displacement of water and it was discovered by Archimedes.

Complete answer:
To find the volume of an irregular object we can use the method of displacement of water. The procedure is given below-
Take a cylinder in which the object can easily be placed and there is a good amount of space left behind and this cylinder must have the readings. Now, fill the cylinder with water so that the object can fully be submerged. Note the reading the cylinder and mark this volume as ${{V}_{0}}$ or we can say this is the initial volume.
Now, place the object in the water and submerge it properly so that the whole object is fully inside the water. Due to this submerging, there will be a rise in the volume of the water. Note the reading form the cylinder and mark this volume as ${{V}_{F}}$ or we can say this is the final volume.
Now, when we take the difference between the final volume and the initial volume, we get the volume of the irregular object. This is given below:
${{V}_{object}}={{V}_{F}}-{{V}_{0}}$
This method was first discovered by Archimedes.

Note:
The rise in the level of water is due to the fact that when the object is immersed in the water then there is a buoyant force that acts on the water which raises the level of the water.