Answer:
The concentration is 
Explanation:
From the question we are told that
The absorbance is 
The length is 
Generally absorbance is mathematically represented as

where
is the molar absorptivity of FeSCN2 with a value 
and
is the equilibrium concentration of FeSCN2
So

substituting values


The two dimensions of aluminum foil are given 13.72 cm and 8.63 cm respectively with mass 3.1 g.
The density of aluminum is
. It is defined as mass per unit volume thus, volume of aluminum can be calculated as follows:

Putting the values.

The volume of cuboid is
, the length and breadth are given, height can be calculated as follows;

Putting the values,

Or, approximately 9.7\times 10^{-3}cm
Therefore, thickness of aluminum foil is 
Filtration is useful for separating sediments that are carried in water for easy drinking without the risk of disease - an example of this is a water purifier
Answer:
A chemical property is any of a material's properties that becomes evident during, or after, a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity. ... They can also be useful to identify an unknown substance or to separate or purify it from other substances.