Overview
A 50% solution of sodium hydroxide is a clear and colorless liquid. It is available is in premade format from a number of suppliers1-3. It causes severe skin burns and eye damage. The solution may be corrosive to metals. The following are know characteristics of the solution.
Density of Sodium Hydroxide = 1.515 g/ml
Molecular weight of NaOH = 40.00 g/mole
Concentration of Sodium Hydroxide = 50% (% by mass, wt/wt)
Calculation
Step 1: Calculate the volume of 100 grams of Sodium Hydroxide solution.
Formula:
Density = weight / volume or
Volume = weight / density
The volume of 100 g of Sodium hydroxide solution: 100/1.515 = 66.0066 ml
The volume of 100 g of Sodium hydroxide solution is 66.0066 ml which means 50g of NaOH is present in 66.0066 ml of Sodium hydroxide solution.
Step 2: Calculate how many grams of NaOH is present in 1000 ml of Sodium hydroxide solution.
66.0066 ml of Sodium Hydroxide contains = 50 grams of NaOH
1 ml of Sodium Hydroxide will contain = 50/66.0066 grams of NaOH
1000 ml of Sodium Hydroxide will contain = 1000 x 50/66.0066 = 757.50 grams of NaOH
1000 ml of Sodium hydroxide solution will contain 757.50 grams of NaOH.
40 g of NaOH is equal to 1 mole.
1 g of NaOH will be equal to 1/40 moles.
757.50 g of NaOH will be equal to = 757.50 x 1/40 = 18.9375 moles
Therefore, 1 liter of sodium hydroxide solution contains 18.9375 moles or in other words, molarity of 50% (w/w) Sodium Hydroxide is equal to18.9375 M.
References