Concentration with Examples


Concentration is the amount of solute in given solution. We can express concentration in different ways like concentration by percent or by moles.

1) Concentration by Percent:

It is the amount of solute dissolves in 100 g solvent. If concentration of solution is 20 %, we understand that there are 20 g solute in 100 g solution.


concentration formula







Example: 10 g salt and 70 g water are mixed and solution is prepared. Find concentration of solution by percent mass.


Mass of Solute: 10 g

Mass of Solution: 10 + 70 = 80 g

80 g solution includes 10 g solute

100 g solution includes X g solute


X=12,5 g %

Or using formula;

Percent by mass=10.100/80=12,5 %

Example: If concentration by mass of 600 g NaCl solution is 40 %, find amount of solute by mass in this solution.


100 g solution includes 40 g solute

600 g solution includes X g solute


X=240 g NaCl salt dissolves in solution.

Example: If we add 68 g sugar and 272 g water to 160 g solution having concentration 20 %, find final concentration of this solution.


Mass of solution is 160 g before addition sugar and water.

100 g solution includes 20 g sugar

160 g solution includes X g sugar


X=32 g sugar

Mass of solute after addition=32 + 68=100 g sugar

Mass of solution after addition=272 +68 + 160=500 g

500 g solution includes 100 g sugar

100 g solution includes X g sugar


X= 20 % is concentration of final solution.

2) Concentration by Mole:

We can express concentration of solutions by moles. Number of moles per liter is called molarity shown with M.





Example: Using 16 g NaOH, 200 ml solution is prepared. Which ones of the following statements are true for this solution?(Molar mass of NaOH is 40 g)

I. Concentration of solution is 2 molar

II. Volume of the water in solution is 200 ml

III. If we add water to solution, moles of solute decreases.

Solution: Moles of NaOH

I. nNaOH=16/40=0,4 mole

V=200 mL= 0,2 Liters

Molarity=0,4/0,2=2 molar

I is true

II. Since volume of solution is 200 mL, volume of water is smaller than 200 mL. II is false.

III. If we add water to solution, volume of solution increases but moles of solute does not change.

Example: 4,4 g XCl2 salt dissolves in water and form 100 ml 0,4 molar XCl2 solution. Find molar mass of X. (CL=35)



n=M.V where V=100mL=0,1 L and M=0,4 molar

n=0,1.0,4=0,04 mole

If 0,04 mole XCl2 is 4,4 g

1 mole XCl2 is ? g


?=110 g XCl2

Molar mass of XCl2=X+2.(35)=110

X=40 g/mole


3) Molality:

Molality is the another expression of concentration of solutions. It is denoted with "m" and formula of molality is;






4) Normality:

We can express concentration in another way with normality using equivalents of solutes.






Equivalents can be defined as; number of moles of H+ ion in acids and  OH- ion in base reactions. For example; 1 mole H2SO4 gives 2 H+ ion, equivalent of H2SO4 is 2. We find equivalent weight;









Solutions Exams and  Problem Solutions



concentration tutorials
addition two solutions what is final concentration
concentration chemistry examples
express the concentration of a 20 NaOH solutions as a mass/ volum percentage(%)
20g is to 200ml as 100 ml is to x as a proportion
n=MV molarity
what is the concentration of a solution with 10g of salt dissolved in 40g of solution
find final concentration chemistry
finding final concentration of a solution when adding water
examples of solutions having final concentrations
example problem on expressing concentration in percent by mass
mass/mass percent concentration of a solution examples
mass of solutions chemistry
normality in chemistry example problem
example of molality
find final concentration
how to find concentration of a solution after adding water
express concentration in % m/v
examples of percentage concentration m/v and its solution
problems on concentration of solutions in chemistry
how do you express concentration as amount
what is the concentration of a solution when 10g in 100g of water
concentration chemistry example
final concentration chemistry
Formula for molality
chemistry examples of concentration
normality chemistry sample
factors affecting concentration solution of NaOH
percent concentration examples
how to find the final concentration of a solution ml
example problems on concentration
concentration solutions tutorials
final concentration of a solution
sample problem in percentage by mass of solute
examples on solution concentration
examples of percentage by mass concentration
sample problems for concentration in chemistry
finding final concentration after adding water
concentration of solutions-chemistry and example problems
example of Normality chemistry
chemistry normality example
sample problem in concentration on solutions
n=v/mv chemistry
percent by mass concentration sample problems
mass concentration example
10 problem example with solution of molality
how to find solute concentration from percentage
molality sample problems w/ formula