#"28.5 g"# of iron shot is added to a graduated cylinder containing #"45.5 mL"# and the volume of water in the cylinder increases to #"49.1 mL"#. What is the density and specific gravity of iron?

1 Answer
Meave60
Nov 8, 2014

The density of iron is #"7.9 g/cm"^3"# and its specific gravity is #7.9#.

Explanation:

Density is mass per unit of volume of a substance. The density equation is:

#"density"# = #"mass"/"volume"#

Specific gravity is the ratio between the density of a substance and the density of a reference substance, usually water at #"4"^o"C"#, which is #"1.000kg/L"#, which is equal to #"1.000g/cm"^3"#. http://www.britannica.com/EBchecked/topic/558700/specific-gravity

In order to determine the density of the iron shot, you must know its mass and volume. The volume is the amount of water that was displaced. The mass is given as 28.5 g.

#"Volume"_"iron shot"# = #"49.1mL - 45.5mL = 3.6mL = 3.6cm"^3# (#"1mL"# = #"1cm"^3#)

#"Density"_"iron shot"# = #"28.5g"/"3.6cm"^3"# = #"7.9g/cm"^3#

#"Specific"# #"gravity"_"iron shot"# = #((7.9color(red)cancel(color(black)("g")))/(color(red)cancel(color(black)("cm"^3))))/((1.000color(red)cancel(color(black)("g")))/(color(red)cancel(color(black)("cm"^(3)"))))#= #"7.9"#*

*Specific gravity is a dimensionless value because the density units cancel.

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