Molarity Notes

Molarity

Molar Concentration (c)

  • Molar concentration, also known as molarity, is defined as the amount (in moles) of solute dissolved in 1 L of solution.
  • It is expressed in units of mol/L, which can be represented by M. Note that this M is different from molar mass.
  • Example: A 6 M HCl solution means the solution has a concentration of 6 mol/L HCl.
  • Equation:
    Molar concentration (c)=amount of solute (mol)volume of solution (L)Molar \space concentration \space (c) = \frac{amount \space of \space solute \space (mol)}{volume \space of \space solution \space (L)}

Example 1

  • Determine the molarity of a saline solution with 0.74 mol NaCl (s) dissolved in 0.30 L of solution.

Example 2

  • Calculate the molar concentration of 15 g of CuSO4CuSO_4 (s) dissolved in 85 mL of solution.

Example 3

  • Determine the mass of Ca(OH)2Ca(OH)_2 dissolved in 34 mL of a 0.347 mol/L solution.

Example 4

  • What volume of a 0.923 mol/L aqueous solution contains 15.2 g of Na<em>2CO</em>3Na<em>2CO</em>3 (aq)?