Explain using dilution formula how to prepare 0.2M hcl acid from 37% concentrated hcl acid
Better to use ml of concentrate to be diluted to specified volume. Vol Conc(ml) = [(Molarity Needed)(Volume of Soln in Liters)(formula wt of solute)]/[(Decimal Fraction of Solute in concentrate)(Density of conc soln)]
Let's assume you need 250 ml of 0.20M HCl(aq) solution.
ml conc needed = [(0.20M)(0.250L)(36g/mol)]/[(.37)(1.14g/ml)] = 4.2 ml of concentrate needed.
However, when diluting a strong acid such as HCL(37%), 1st transfer a small quantity of water into the mixing vessel (in this case ~100ml) then slowly add the 4.2ml of concentrated HCl. Adding solvent water into 4.2ml of concentrated HCl(aq) may cause the solution to flash/splash because of rapid heating during the mixing process. Addition of conc strong acid into a small quantity of water be for dilution to final volume avoids this danger.
After mixing the 4.2ml into the 100ml of solvent water, then add the remaining solvent water up to but not to exceed the 250ml mark.
Using the dilution equation gives the same volume of concentrate. HCl(37%) is ~12M... (Molarity)(Volume)concentrate = (Molarity)(Volume)diluted soln => (12)V(ml) = (250ml)(0.20M). In this, you are determining how much of the concentrate you will need (in mls.) to dilute to desired volume. Remember A&W Root Beer... Add Acid to Water(small quantity) then dilute to needed volume.
With careful attention to volumetric accuracy, either method will give an experimental error of less than ±10%.
To prepare a 0.2 M HCl solution from a 37% concentrated HCl acid, you can use the dilution formula:
C1V1 = C2V2
Where:
C1 = initial concentration of the solution (in this case, 37%)
V1 = initial volume of the solution you have
C2 = final concentration you want to achieve (in this case, 0.2 M)
V2 = final volume of the solution you want to prepare
First, convert the concentration of the concentrated HCl acid from percentage to molarity. To do this, you need to know the density of the solution. Assuming the density is 1.2 g/mL, you can calculate the molarity using the formula:
% Concentration = (Volume of solute / Volume of solution) x 100%
Molarity (M) = (Mass of solute / Molar mass of solute) / Volume of solution
Let's say you want to prepare 100 mL of the 0.2 M HCl solution.
Step 1: Find the molar mass of HCl:
H = 1 g/mol
Cl = 35.5 g/mol
Molar mass of HCl = 1 + 35.5 = 36.5 g/mol
Step 2: Calculate the mass of HCl needed for the desired volume:
0.2 mol/L x 0.1 L = 0.02 mol
Mass of HCl = Molar mass x Moles
= 36.5 g/mol x 0.02 mol
= 0.73 g
Step 3: Calculate the volume of concentrated acid needed:
Density of 37% HCl acid = 1.2 g/mL
Mass = Volume x Density
Volume of concentrated acid = Mass / Density
= 0.73 g / 1.2 g/mL
≈ 0.61 mL
Remember, in this case, you need to be careful when handling concentrated HCl acid as it is highly corrosive and should be handled with caution. Make sure to use appropriate safety measures, such as wearing gloves and goggles, and work in a well-ventilated area.
Once you have the required volume of concentrated HCl acid (0.61 mL), you can add it to a container and then add distilled water to reach the desired final volume (in this case, 100 mL).
Finally, mix well to ensure proper dilution, and you'll have a 0.2 M HCl solution.