Molarity of 37% (w/w) Hydrochloric Acid (HCl)

OVERVIEW

  • A 37% (w/w) Hydrochloric Acid is a clear colorless aqueous solution of Hydrogen chloride (HCl) gas. It can be purchased from many commercial suppliers.
  • % refers to solution concentration in percentage and “(w/w)” refers to solute and solution amount given in grams (i.e., percentage by weight). This means a 37% (w/w) Hydrochloric acid contains 37 g of HCl per 100 g of solution.
  • The density of 37% (w/w) Hydrochloric acid solution is 1.2 g/ml at 25° C. This means the weight of the 1 ml of hydrochloric acid solution is 1.2 g at 25°C.
  • Molarity refers to the number of moles of the solute present in 1 litre of solution. To calculate the Molarity of 37% (w/w) Hydrochloric Acid (HCl), you need to know how many moles of HCl are present in 1 liter of solution.
  • In simple words, 1 mole is equal to the molecular weight of the substance. For example, 1 mole of Hydrogen chloride is equal to 36.46 g of hydrogen chloride (Molecular Weight: 36.46).
  • To calculate the molarity, one must first calculate how much Hydrogen chloride is present in 1 L of 37% Hydrochloric acid. Once we know the amount of HCl present in 1 L solution, we can calculate the molarity of the solution by dividing the HCl amount by the molecular weight.
  • Calculator: Converting Percentage by Mass to Molarity

37% hydrochloric acid to moles per liter

Calculation procedure

Known values 
Molar mass of Hydrogen chloride36.46 g/mole
Concentration of Hydrochloric acid 37% (% by mass, w/w)
Density of 37% Hydrochloric acid
1.2 g/ml

Step 1: Calculate the volume of 100 grams of Hydrochloric acid.
Formula:

Density = WeightVolume

OR

Volume = WeightDensity

The volume of 100 g of Hydrochloric acid : 1001.2 = 83.33 ml

Note: 37% (w/w) Hydrochloric acid means that 100 g of Hydrochloric acid contains 37 g of HCl.

The volume of 100 g of Hydrochloric acid is 83.33 ml which means 37 g of HCl is present in 83.33 ml of Hydrochloric acid.

Step 2: Calculate how many grams of HCl is present in 1000 ml of Hydrochloric acid.

83.33 ml of Hydrochloric acid contains   = 37 grams of HCl
1 ml of Hydrochloric acid will contain      =   3783.33 grams of HCl

1000 ml of Hydrochloric acid will contain = 1000 x 3783.33  = 444.01776 grams of HCl

1000 ml of Hydrochloric acid will contain 444.01776 grams of HCl.

Step 3: Calculate the number of moles of HCl in 444.01776 grams of HCl.

36.46 g of HCl is equal to 1 mole.

1 g of HCl will be equal to 136.46 moles.

444.01776 grams of Hydrogen chloride will be equal to = 444.01776 x 136.46 = 12.178 moles

Therefore, we can say that 1 liter of Hydrochloric acid contains 12.178 moles of HCl or in other words molarity of 37% (w/w) Hydrochloric acid is equal to 12.178 M.

Calculator – Calculate the molarity of concentrated Hydrochloric acid (HCl)

Use Calculator to calculate the molarity of concentrated Hydrochloric acid (HCl) when concentration is given in % by mass (w/w)

Hydrogen Chloride (HCl) Molecular weight: 36.46 g/mole

Concentration of Hydrochloric acid: % (w/w)
(Change the % (w/w) concentration)

Density of Hydrochloric acid: g/ml
 (Change the density)

Molarity of Hydrochloric acid: 12.178 M

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Author: admin

9 thoughts on “Molarity of 37% (w/w) Hydrochloric Acid (HCl)

  1. I think the calculation above is wrong. I think the proper answer is as follows:
    37w/w% means that of 1000g of solution 370g is HCl. 370g / 36.46g = 10.15M

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