What is molar concentration of 5% solution of sodium hydroxide?

To convert the concentration we can use equation 10.8:

However, wee need two additional informations: molar mass and density of the solution.

Molar mass of NaOH is 40.00 g/mol, in density tables you can find value of 5% NaOH solution density - 1.0554 g/mL.

Knowing these values we can just put them into formula to get
10×5×1.0554/40.00=1.32 M.

Using for conversion concentration conversion calculator you don't have to look for density tables nor calculate molar mass - it is enough to select sodium hydroxide from the list of substances and enter 5 as w/w percentage concentration. Everything else happens automatically. Check example of concentration conversion.