Determination of the density of solid by using a spring balance and a measuring cylinder

Aim

To determine the density of solid (denser than water) by using a spring balance and a measuring cylinder.

Materials Required

Spring balance, measuring cylinder, water, solid body (denser than water)

Theory

The density of a substance is defined as its mass per unit volume.

i.e., Density =

S.I. unit of volume:- Kg/m³

Procedure

1. Firstly find the least count and zero error of spring balance.
2. Suspend the given solid body from the hook of the spring balance and find out the true weight of the solid body. Let it be m gf. Therefore, mass of the given solid body is m g.
3. Take the measuring cylinder and half fill it with water. Note the initial reading of the cylinder.
4. Gently immerse the given solid body completely in water and note the final reading of cylinder.
5. Repeat the steps 3 and 4 thrice and calculate the mean of the three observations taken.

Observation

Least count of spring balance = 5 gf
Zero error of spring balance = ± 0 gf
Weight of solid body in air = 20 gf
Mass of solid body in air = 20 g

S. No.	Initial volume of water (V1)	Final volume of water (V2)	Volume of solid (V2– V1)
1.	155 ml	162.5 ml	7.5 ml
2.	210 ml	218 ml	8 ml
3.	220 ml	227.5 ml	7.5 ml

Calculation

Mean volume of the solid body = = 7.67 ml

Density = = ≈ 2.6 g/ml

Result

The density of the given solid = 2.6 g/ml = 2.6 g/cm³

Precautions

1. The concave surface reading of liquid should be taken parallel to eye from measuring cylinder.
2. The solid should not touch the sides or bottom of the cylinder.
3. The solid should be completely immersed in liquid.
4. While taking the reading of measuring cylinder, keep your eye in horizontal plane with liquid level.

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