Mass And Molar Concentration
Molar concentration (also called molarity) is the number of moles of solute (the substance being dissolved) per litre (dm³) of solution.
Basically molar concentration is the concentration of the number of moles

Example - 1
You dissolve 0.5 moles of NaCl in 1.0 dm³ of water. What is the molar concentration?

Standard Solution
A solution whose concentration is known precisely
Titration
A method of quantitative analysis using solutions
Example -2
25.0 cm³ of HCl is neutralized by 20.0 cm³ of NaOH of concentration 0.100 mol/dm³. What is the concentration of HCl?
