Question

How is concentration of a solution measured?

Answer 1

Hint: A solution is made up of two components, solute and solvent. In chemistry we define the concentration of solution as the amount of solute dissolved in solution. It can be measured by dividing the weight of solute in grams to the volume of solution.

Complete step-by-step answer:In general, the concentration of the solution can be represented or measured with the help of formula as shown:
Concentration of solution = $\dfrac{weight\,of\,solute\,in\,grams}{Volume\,in\,litres}$
There are various different ways in which the concentration of the solution can be measured. They are as follows:
a. Molarity: It is the number of moles of solute contained in one liter of solution. It is a commonly used method for measuring the concentrations.
$Molarity\,=\,\dfrac{\,number\,of\,moles\,of\,solute}{Volume\,of\,solution\,\,\left( in\,l \right)}$
b. Molality: It is the number of moles contained in one kg of solvent.
$Molality\,=\,\dfrac{number\,of\,moles}{mass\,of\,solvent}$
c. Mass percentage: It is expressed in terms of mass percentage of solute to the solution. It can be represented by the formula
$Mass\,percentage\,=\,\dfrac{Mass\,of\,component}{total\,mass\,of\,solution}$ the formula for parts per million is given by
d. Volume percentage: it is expressed in terms of volume percentage of a component of solution to the solvent. It is given by formula
$Volume\,percentage\,=\,\dfrac{Volume\,of\,component}{Total\,volume\,of\,solution}$
e. Concentration in parts per million: it is expressed in terms of weight in weight.
$ppm\,=\,\dfrac{number\,of\,the\,parts\,of\,a\,component}{Total\,number\,of\,parts\,of\,all\,components}\,\times \,{{10}^{6}}$
So, concentration of solution can be measured through above defined methods.

Note:Whenever one measures the concentration of a given solution, keep attention on the units of the quantities involved in the formula. Always use significant figures rules to express the decimal answer to its closest approximate value.