Molarity & Molar solution

Molarity is defined as the number of moles of solute dissolved in 1 litre of solution: this is

                      Molarity = number of moles of solute 
                                             L solution

Molarity has a unit moles per litre (Mol L^-1). By convention , we use square brackets[] to represent molarity.

Determine how many grams of Na⁺ would be present in 1L of sea water.

                                     1.06% = 1.06 g Na⁺  so to find how much in 1L multiply by 10

                                                     100mL

                                

                                      1.06% = 10.6 g Na⁺

                                                                       ^1000mL

Determine how any moles in are present in 10.6 g of Na⁺

                                  Moles Na⁺  = 10.6 g            =    0.46 moles.

                                                         23.0 g/mol

Thus the seawater has the molarity of Na+ of 0.46M.