[Sis290025]

 Sodium hydroxide is available commercially as a 50.0% by weight aqueous solution. The density of the solution is 1.53 g/mL. Calculate the molarity of this sodium hydroxide solution.

a.125. M

b.0.450 M

c.25.0 M

d.19.1 M

M = mol NaOH / L solution

Think that we have 50 g NaOH and 50 g of H2O.  

50 g NaOH * (1 mol/39.998 g NaOH) = 1.25006 mol NaOH

Volume = mass/density = 100 g solution/ (1.53 g/mL) = 65.359 mL = 0.065359 L solution

1.25006 mol NaOH/0.065359 L = 19.1 M

Thanks.

[Borek]

OK

http://www.chembuddy.com/?left=concentration&right=percentage-to-molarity