Introduction to Chemistry

for Allied Health Sciences

Density & Specific Gravity

Kirk HunterChemical Technology Department

Texas State Technical College Waco

Density

DENSITY

MASS PER UNIT VOLUME

Volume

Massd

DENSITY

FOR SOLIDS AND LIQUIDS:

milliliter

grams

Volume

Massd

DENSITY

FOR SOLIDS AND LIQUIDS:

3cm

grams

Volume

Massd

Note: 1 cm3 1 mL

DENSITY

FOR GASES:

liter

grams

Volume

Massd

DENSITYExample:Calculate the density of a

metal if 356 grams occupies a volume of 43.1 mL.

mLg26.8

milliliter1.43

grams356

Volume

Massd

Specific Gravity

SPECIFIC GRAVITY

reference

cetansubs

d

d.gr.sp

SPECIFIC GRAVITY

Reference SubstanceWATER AT 4oC

ml

g000.1d C4

watero

SPECIFIC GRAVITY

mlg

000.1

d

d

d.gr.sp cetansubs

water

cetansubs

Note: Specific Gravity has NO units.

SPECIFIC GRAVITY

Example: The density of gold is 19.3 g/mL. What is its specific gravity?

ml

g3.19dAu

3.19

mLg

000.1

mLg

3.19

mlg

000.1

d.gr.sp Au

SPECIFIC GRAVITY

Notation

19.325/4

SPECIFIC GRAVITY

Notation

19.325/4

19.3 specific gravity

SPECIFIC GRAVITY

Notation

19.325/4

25 temperature of substance

measured in ºC.

SPECIFIC GRAVITY

Notation

19.325/4

4 temperature of reference substance

measured in ºC.