Concentration refers to the amount of substance present.
The term concentration refers to the amount of substance present. There are many units that could be used for concentration of a solution. This makes reference easy.
To express the concentration in milligram per liter;
45/1000/1 L = 0.045 mg/L
To express the concentration in molarity;
Number of moles = mass/molar mass = 45.00 g /106 g/mol = 0.42 moles
Molarity = 0.42 moles/1 L = 0.42 M
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