A solid weighs 100g in air,75g in water and 70g in oil.Calculate the relative density of oil.
It has mass of 100 g
It lost 25 g in water so its volume is 25 cm^3
It lost 30 g in oil so the mass of oil displaced by its 25 cm^3 volume was 30 g
so density of the oil = 30 g/25cm^3
= 1.2 g/cm^3 = 1.2 times water density.
By the way most oil floats on water :)
So you considered oil as mass right?
Very important otherwise you lose 1 mark
But it seems the calculation is wrong bcw Density= Mass÷Volume
To calculate the relative density of oil, we need to compare the density of the oil to the density of water.
The density of an object is defined as its mass divided by its volume.
We are given that the solid weighs 100g in air, 75g in water, and 70g in oil.
To calculate the volume of the solid, we need to subtract the mass of the displaced water (or oil) from the mass of the solid.
In this case, the volume of the solid in water is calculated as follows:
Volume of solid in water = mass of solid in air - mass of solid in water
Volume of solid in water = 100g - 75g = 25cm^3
Similarly, the volume of the solid in oil is calculated as follows:
Volume of solid in oil = mass of solid in air - mass of solid in oil
Volume of solid in oil = 100g - 70g = 30cm^3
Next, we need to calculate the densities of the water and oil.
Density of water = mass of water / volume of solid in water
Density of water = 75g / 25cm^3 = 3g/cm^3
Density of oil = mass of oil / volume of solid in oil
Density of oil = 70g / 30cm^3 = 2.33g/cm^3
Finally, we can calculate the relative density of oil by dividing the density of oil by the density of water:
Relative Density of oil = Density of oil / Density of water
Relative Density of oil = 2.33g/cm^3 / 3g/cm^3 = 0.778