Describe the preparation of 100 mL of 6.0 M HCL from a concentrated solu-tion that has a specific gravity of 1.18 and is 37% (w/w) HCl (36.5 g/mol).
First you determine by calculation the molarity of the 37% solution.
1.18 g/mL x 1000 mL x 0.37 x (1/36.5) = ? mols/L = M which I will call M1.
Thsn use the dilution formula of
M1 x mL1 = M2 x mL2
M1 from the above calculation, mL1 = solve for this.
M2 = 6 M
mL2 = 100 mL
Substitute and solve for mL1. Pipet the volume mL1 from the concentrated solution and add it to a 100 mL volumetric flask. Add distilled or deionized water to the 100 mL flask until the water level reaches the mark on the neck of the flask. Stopper, mix thoroughly, label. Done.
To prepare 100 mL of 6.0 M HCl from a concentrated solution with specific gravity 1.18 and 37% (w/w) HCl, follow these steps:
Step 1: Determine the moles of HCl needed
To calculate the moles of HCl needed, we will use the formula:
moles = concentration (M) × volume (L)
Given that we need 100 mL (0.1 L) of 6.0 M HCl, we can calculate the number of moles as follows:
moles of HCl = 6.0 mol/L × 0.1 L = 0.6 moles
Step 2: Calculate the mass of the concentrated HCl solution needed
To find the mass of the concentrated HCl solution needed, we will use the formula:
mass = volume (L) × specific gravity (g/mL) × density (g/mL)
Given that the specific gravity of the concentrated HCl solution is 1.18 and we require 100 mL (0.1 L) of the solution, we can calculate the mass as follows:
mass of concentrated HCl solution = 0.1 L × 1.18 g/mL = 0.118 g
Step 3: Convert the mass of the concentrated HCl solution to moles
To convert the mass of the concentrated HCl solution to moles, we need to use the molar mass of HCl, which is 36.5 g/mol. We can calculate the number of moles as follows:
moles of HCl in concentrated solution = mass of concentrated solution (g) / molar mass of HCl (g/mol)
moles of HCl in concentrated solution = 0.118 g / 36.5 g/mol = 0.00323 moles
Step 4: Calculate the volume of the concentrated HCl solution needed
To find the volume of the concentrated HCl solution needed, we will use the formula:
volume = moles / concentration (M)
Given that there are 0.00323 moles of HCl in the concentrated solution and we want to make a 6.0 M HCl solution, we can calculate the volume as follows:
volume of concentrated HCl solution = 0.00323 moles / 6.0 mol/L = 0.00054 L (0.54 mL)
Step 5: Dilute the concentrated HCl solution to 100 mL with distilled water
To prepare the desired 6.0 M HCl solution, add the volume of the concentrated HCl solution (0.54 mL) to 100 mL of distilled water in a container. Mix well to ensure homogeneity.
Now, you have successfully prepared 100 mL of 6.0 M HCl solution from the given concentrated solution.
Note: Always remember to handle concentrated acids with caution, wear appropriate protective equipment, and follow proper laboratory procedures.
To prepare 100 mL of 6.0 M HCl from a concentrated solution with a specific gravity of 1.18 and 37% (w/w) HCl, we can follow these steps:
Step 1: Determine the amount of HCl needed
To calculate the amount of HCl needed, we need to consider the desired molarity and volume. Molarity (M) is defined as moles of solute divided by liters of solution. In this case, we want to make 100 mL (0.1 L) of 6.0 M HCl.
Moles of HCl = Molarity × Volume
Moles of HCl = 6.0 mol/L × 0.1 L
Moles of HCl = 0.6 mol
Step 2: Determine the mass of the concentrated solution needed
The solution has a specific gravity of 1.18, which is the ratio of its density to the density of water. Since the solution has a higher density than water, we can assume that 100 mL of the solution weighs 1.18 times the weight of 100 mL of water. The density of water is approximately 1 g/mL, so the weight of the solution is 1.18 g/mL.
Mass of the concentrated solution = Volume × Density
Mass of the concentrated solution = 100 mL × 1.18 g/mL
Mass of the concentrated solution = 118 g
Step 3: Calculate the mass of HCl in the concentrated solution
The solution is 37% (w/w) HCl, which means that 100 g of the solution contains 37 g of HCl.
Mass of HCl in the concentrated solution = Mass of the concentrated solution × % HCl
Mass of HCl in the concentrated solution = 118 g × (37/100)
Mass of HCl in the concentrated solution = 43.66 g
Step 4: Calculate the volume of the concentrated solution needed
To find the required volume of the concentrated solution, we need to know its molarity, which can be calculated using the mass and molar mass of HCl.
Molarity = Moles of solute / Volume of solution
Volume of solution = Moles of solute / Molarity
Since we already know the moles of HCl (0.6 mol) and its molar mass (36.5 g/mol), we can calculate the volume as follows:
Volume of concentrated solution = Moles of HCl / Molarity
Volume of concentrated solution = (43.66 g / 36.5 g/mol) / 6.0 mol/L
Volume of concentrated solution = 0.201 L or 201 mL
Therefore, to prepare 100 mL of 6.0 M HCl, you would need to measure 201 mL of the concentrated solution and then dilute it to 100 mL with water.