Molarity of glacial acetic acid (99.7%, w/w, CH3COOH)

Molarity of glacial acetic acid (99.7%, w/w, CH3COOH)

Overview:

  • Glacial acetic acid is a clear colourless liquid. A 99.7% (w/w) concentrated glacial acetic acid can be obtained from different suppliers. (see suppliers)
  • 99.7% (w/w) glacial acetic acid means that 100 grams of glacial acetic acid contains 99.7 grams of acetic acid.
  • The density of glacial acetic acid is 1.049 g/ml at 25°C that means that weight of the 1 ml of glacial acetic acid is 1.049 gram at 25°C.
  • Molarity refers to number of moles of the solute present in 1 litre of solution.
  • In simple words, 1 mole is equivalent to atomic weight of the substance. For example, 1 mole of acetic acid is equivalent to 60.05 grams of acetic acid (molecular weight = 60.05).

Related content

Calculation procedure:

Known values:
Density of glacial acetic acid :                                                  1.049 g/ml
Molecular weight of acetic acid (CH3COOH):                         60.05 g/mole

Concentration of glacial acetic acid (% by mass, wt/wt):     99.7%

Step 1: Calculate the volume of 100 grams of glacial acetic acid solution.

Formula:
Density     =     weight / volume       or

Volume     =     weight / density

Volume of 100 grams of glacial acetic acid = 100/1.049 = 95.329 ml

Note: 99.7% (w/w) glacial acetic acid means that 100 grams of glacial acetic acid contains 99.7 grams of acetic acid.

The volume of 100 gram of glacial acetic acid is 95.329 ml. That means 99.7 grams of acetic acid is present in 95.329 ml of glacial acetic acid.

Step 2: Calculate how many grams of acetic acid is present in 1000 ml of glacial acetic acid.

95.32 ml of glacial acetic acid contains       =   99.7 grams of acetic acid
1 ml of glacial acetic acid will contain         =  99.7/95.329 grams of acetic acid

1000 ml of glacial acetic acid will contain   =  1000 x 99.7/95.329 = 1045.85 grams of acetic acid

1000 ml of glacial acetic acid will contain 1045.85 grams of acetic acid.

Step 3: Calculate number of moles of acetic acid present in 1045.85 grams of acetic acid.

60.05 grams of acetic acid        =     1 mole
1 gram of acetic acid                 =      1/60.05 moles

1045.85 grams                            =    1045.85 x 1/60.05     =     17.416 moles

Therefore, we can say that 1 liter of glacial acetic acid contains 17.416 moles or in other words molarity of glacial acetic acid (99.7% w/w, density 1.049 g/ml) is equal to 17.416.