   About eFormulae.com | Advertise with us | Contact | Algebra |  Trigonometry | Limits | Derivatives | Integrals | Calculus | Vectors | Statistics | More | Units and Measurements | Motion | Energy | Formulae | Time | Mass | Meter | Unit Converter | General Chemistry Formulae | Thermodynamics | Kinetics | Electrochemistry | Periodic Table | More Applied Mechanics | Strength of Materials | Surface Speeds | Drill Sizes | Threads | More Blog |  Advertisers

 Bhagavada Geeta Saar Translation of the Bhagavada Geeta. MfgTalk.com All about Manufacturing Mahagauri.com Photos of Goddess Durga .

 Chemistry Formulae
Specific Gravity

 Determination of Specific Gravity Specific Gravity of Certain Materials

Specific Gravity of Solids

The density of a substance is its mass per unit volume, i.e., its The Specific Gravity of a substance is the ratio of the weight of nay volume of the substance to the weight of an equal volume of water at 4°C.

Specific gravity of a substance The specific gravity of a substance is really a relative density, i.e. its relative density to that of water at 4°C

In C.G.S. system, the mass of 1 c.c. of water at 4°C is one gram, its density is, therefore, 1 gm. per c.c.

In M.K.S. it is 1 kg. per liter

In F.P.S. system, the mass of 1 c.ft. of water is 62.5 lbs. or the density is 62.5 lb. per c.ft.

Hence in C.G.S. system, the density of a substance is numerically equal to its specific gravity. On the other hand, the density of a substance in F.P.S. unit is numerically equal to 62.5 X specific gravity of the substance.

Determination of Specific Gravity

a) By Archimedes' Principle:

1) To find the Sp. Gravity of solid heavier than water.

Let the weight of the solid in air = W1 gm.

Weight of the solid in water= W2 gm

The weight of the same volume of water as that of the solid = (W1-W2) gms. To take the weight of the body in water, it is suspended by means of a fine thread from the hook of the left pan and made to sink completely in water contained in a beaker. The beaker is placed on a small wooden bridge, which is put across the pan in such a way that the bridge or the beaker does not touch any part of the pan of the balance.

Therefore, 2) Solid Lighter than Water

Let the weight of solid in air = W1 gm

Take another heavy body, called a sinker, such that the two tied together may sink in water.

Let the weight of the solid and sinker both in water = W2 gm

Weight of the sinker of the solid and sinker both in water = W3 gm

Weight of solid in water = W2 - W3 gms.

= W1 × (W2  W3) = W1 × (W2  W3)

Therefore, 3) Solid Soluble in Water

The specific gravity of a solid soluble in water can be found by immersing the solid in a liquid of known specific gravity in which the solid is insoluble.

Determine the specific gravity of the solid relative to the liquid. Then the actual specific gravity of the solid will be obtained by multiplying this value with the specific gravity of the liquid.

Specific gravity of solid where              W1 = wt. of solid in air;

W2 = wt. of solid in the given liquid:

d = sp. gr. of the liquid.

b) By the Specific Gravity Bottle.

It is a small glass bottle usually of 25 or 50 c.c. capacity with a slight conical neck. It is fitted with a ground glass stopper which has a fine bore along the whole length. When the bottle is completely filled with any liquid and the stopper is fitted to the mouth, the excess of the liquid flows out through the hole in the stopper. Thus, the inside volume of the bottle is always kept constant. This bottle is used to find out the specific gravity of a solid in the form of powder or small fragments, and of liquid also. Let the weight of the empty bottle = W1 gm.

The weight of the bottle +powder put inside  = W2 gm.

Weight of the powder  = (W2-W1) gm.

Weight of the bottle + powder water to fill the rest of the bottle = W3 gm.

Now pour out all the contents of the bottle and fill it up with pure water taking care to remove any air bubbles from inside. Let the weight of the bottle when full of water =W4 gm.

Weight of an equal volume of water as that of the powder  = (W4-W1)  (W3-W2) gm.

Hence Sp. Gr. =   