A dilute acid solution (DAS) is a solution made of dilute acid and other compounds. Making DAS requires precise measurements and a good understanding of the chemistry involved. This guide provides step-by-step instructions on how to create a DAS to achieve the desired results.
Dilute Acids Solution
3N Hydrochloric Acid
To prepare a 3 N hydrochloric acid solution, concentrated hydrochloric acid (37% HCl) and distilled water will be required. Here's how to prepare 1 liter of 3 N HCl solution.
Calculation
Let us first calculate the amount of concentrated HCl required to prepare 1 liter of 3 N solution.
Let us find it with the help of the following formula.
mole of solute = molarity x volume (in liters)
For 3 N HCl, the molarity is 3 moles per liter (3N = 3 mol/L).
Therefore, moles of HCl = 3 mol/L x 1 L = 3 mol Since concentrated HCl is 37% by mass and has a density of 1.19 g/mL,
We calculate the mass of HCl needed using this information:
mass of HCl = moles of HCl x molar mass x (1/0.37) x density
The molar mass of HCl is 36.46 g/mol. Plugging in the numbers,
We get
Mass of HCl = 3 mol x 36.46 g/mol x (1/0.37) x 1.19 g/mL = 305.5 g
So, now we need 305.5 grams of concentrated HCl to prepare 1 liter of 3N solution.
3N HCL Preparation Procedure
Take 305.5 gm concentrated HCL in a beaker and now separately in a clean, dry, and heat-resistant container add HCL to about 800 ml of distilled water slowly. To avoid splashing and potential hazards, always mix acid with water, not water with acid.
Gently stir the solution until the HCl is completely mixed.
Add more distilled water to bring the total volume of the solution up to 1 liter.
Mix the solution well and check the pH with a pH meter or litmus paper. It should be around 0.5 pH units or less.
Label the container with the name of the solution, concentration, and date of preparation, and keep the solution in a tightly closed bottle away from heat, direct sunlight, and incompatible substances.
3N Nitric Acid
Take 195 ml of 15.4 M Acid (69% HNO3), take a dry, clean volumetric flask add 800 ml distilled Water then add slowly 195 ml of nitric acid and makeup in one liter.
Phosphoric acid, 9N
To make a 9N solution of phosphoric acid, one has to do these steps:
Calculate the mass of phosphoric acid required using the following formula:
The molar mass of phosphoric acid (H3PO4) is 98 g/mol, and the mass of phosphoric acid needed to make 1 L of 9N solution is calculated as follows:
Mass = (9 N) x (98 g/mol) x (1 L) / (1000 mL)
Mass = 8.82 grams
Firstly, weigh the required amount of phosphoric acid on a digital scale.
Pour the phosphoric acid into a clean, dry 1 L volumetric flask.
Add distilled water to the flask until it reaches the 1 L mark, swirling to dissolve the phosphoric acid.
Verify the concentration of the solution using a pH meter or titration method.
Phosphoric acid is a highly corrosive and potentially dangerous chemical. Appropriate safety measures (such as gloves, eye protection, and a lab coat) should be taken when handling it.
Sulfuric acid, 6 N.
Take a clean, dry volumetric flask and add in distilled water about 800 ml now add 168 ml of 95% sulfuric acid to slowly mix and make up to one liter of distilled water.
