Describe the preparation of 250cm3 of 0.05M of H2SO4 solution given the following stock solution specification; % purity= 98, S.G = 1.84 and Molecular weight= 98
Describe the preparation of 250 cm3 of 0.05M H2SO4 solution given the following stock solution specification; % purity= 98, S.G = 1.84 and Molecular weight=98
First, determine the molarity of the stock solution.
The sp.g. is 1.84 so the density is 1.84 g/mL.
Mass of 1 L of H2SO4 is 1.84 g/cc x 1000 cc = 1840 grams.
Mass of H2SO4 in that 1840 grams is 1850 x 0.98 = 1803 g
mols H2SO4 = g/molar mass = 1803/98 = 18.4 mols is 1 L; therefore, M 18.4.
Then use the dilution formula of
mL1 x M1 = mL2 x M2
mL1 x 18.4 = 250 mL x 0.05
Solve for mL1 (that's mL of the stock solution of 18.4 M), then transfer that volume of the stock into a 250 mL volumetric flask, make to the mark with distilled water, stopper, mix thoroughly and label.
NOTE: For safety you should place distilled water in the volumetric flask until it is about half filled BEFORE adding the stock solution of concentrated H2SO4. You should ALWAYS add acid to water, never water to acid.
Well, preparing solutions always reminds me of cooking, but without the delightful aromas. So, let's get started on this chemical recipe for laughter, I mean, H2SO4 solution!
First things first, since you have a stock solution, we need to calculate the volume of stock solution required to achieve the desired concentration. The formula to calculate this is:
C1V1 = C2V2
Where:
C1 = Concentration of stock solution
V1 = Volume of stock solution
C2 = Desired concentration
V2 = Desired final volume
Now, let's substitute the known values:
C1 = ? (We don't know this yet)
V1 = ? (We'll figure this out)
C2 = 0.05M (Desired concentration)
V2 = 250cm3 (Desired final volume)
Next, we need to convert the given % purity into a decimal. So, 98% purity becomes 0.98.
Now, let's plug these values into the formula:
(0.98)(V1) = (0.05)(250)
To find V1, we divide both sides by 0.98:
V1 = (0.05)(250) / 0.98
Now, let's get our calculators, drum roll, please! *Ba-dum-tss*
After calculating it, we find that V1 is approximately 127.55cm3.
So, to prepare 250cm3 of 0.05M H2SO4 solution using the stock solution, you need to take approximately 127.55cm3 of the stock solution and add water until it reaches the desired final volume.
Congratulations on your scientific culinary skills! Remember to handle chemicals with caution, just like handling hot sauce – it can pack a punch if you're not careful. Enjoy, and happy experimenting!
To prepare 250cm3 of 0.05M H2SO4 solution, we need to calculate the required amount of stock solution. Here's how to do it:
Step 1: Calculate the molecular weight of H2SO4.
The molecular weight of H2SO4 is given as 98 grams/mol.
Step 2: Calculate the number of moles required.
To find the number of moles required, we use the molarity and volume formula:
moles = molarity × volume (in liters)
Since we want a 0.05M solution, the moles of H2SO4 can be calculated as:
moles = 0.05 mol/L × 0.250 L = 0.0125 moles
Step 3: Calculate the mass required.
To find the mass of H2SO4 needed, we can use the formula:
mass = moles × molecular weight
mass = 0.0125 moles × 98 g/mol = 1.225 grams
Step 4: Calculate the volume of the stock solution required.
To determine the volume of the stock solution required, we divide the mass by the density (specific gravity).
volume = mass / density
volume = 1.225 grams / 1.84 g/cm3 = 0.666 cm3
Since the required volume is less than 1 cm3, it is recommended to use a micropipette to accurately measure out the volume of stock solution needed.
In conclusion, to prepare 250 cm3 of 0.05M H2SO4 solution using a stock solution with a purity of 98%, specific gravity of 1.84, and molecular weight of 98 g/mol, you would need to measure out approximately 0.666 cm3 of the stock solution and dilute it to 250 cm3 using a suitable solvent (such as distilled water).