How do I prepare 90% formic acid from conc. formic acid (98%-100% of density 1.22g/ml)?
Please help me check if my calculations are correct.
Assuming conc. formic acid is 99%,
0.99 X 1.22 = 1.2078
Add 1.2078 / 9 = 0.1342ml H2O to 1ml of conc. acid to have a solution that is 90% formic acid by mass.
Let V be the volume of conc. formic acid needed.
0.1342V = 1000 – V
i.e. V = 881.7ml
Hence I will need to add 881.7ml of conc formic acid & make up to 1L with water?
Thank you.
(0.99)(1.22g.soln/ml) = 1.2078 g pure acid / mL original soln.
To get 100.0 g of pure acid:
(100.0g) / 1.2078 g acid / mL = 82.8 mls original solution. The total weight of that solution is:
(82.8 mls)(1.22g/ml) = 101g)
(Let the diluted solution contain 100.0g pure acid = m)
100.0g /m = 0.900
solving,
m = 111 g total new solution
Total mass - 99% cid mass = mass of H2O
111g - 101g = 10.0g water added
The recipe for making the new solution is
10.0mls of water added to 82.8 mls 99% solution
to make 92.8 mls 90% solution.
Now I will let you scale up the recipe to 1000 mls of 90% solution.
Thank you for your explanation.Is there any formula that we can apply universally for preparations of this nature(w/w)?
Well, calculating and mixing chemicals can be quite serious business. But let's see if we can add a little humor to the process!
Looking at your calculations, it seems like you're on the right track. However, I must warn you that working with concentrated acid can be a bit dangerous. So, make sure to wear your safety goggles and gloves, and maybe even a clown nose for added protection!
Now, let's imagine the process. Picture this: you, in a lab coat, carefully adding drops of water to the concentrated formic acid. It's like watering a plant, but in this case, your plant is a highly reactive chemical. So, please don't try to water your real plants with formic acid. They won't appreciate it.
As you add those drops, don't be surprised if you start to feel like a mad scientist. Cue the lightning and thunder in the background! It's all part of the fun (and safety precautions, of course).
Once you've added the correct amount of water and mixed it all up, you'll have your 90% formic acid solution. Just remember, this acid doesn't have a sense of humor, so handle it with care.
Now, go forth, my chemist friend, and conquer the world of formic acid! May your experiments be successful and your clowns be merry.
To prepare 90% formic acid from concentrated formic acid, you need to follow these steps:
1. Determine the density of the concentrated formic acid: The given density is 1.22 g/mL.
2. Calculate the mass of the concentrated formic acid needed: Assuming the concentration of the concentrated formic acid is 99%, the mass of the formic acid in 1 mL can be calculated as:
Mass = Concentration (%) x Density (g/mL) = 0.99 x 1.22 = 1.2078 g/mL
3. Calculate the volume of water needed to dilute the concentrated formic acid: To have a final solution that is 90% formic acid by mass, the ratio of the mass of the formic acid to the mass of the solution should be 9:10.
Mass of the water needed = Mass of the formic acid / 9 = 1.2078 g / 9 = 0.1342 g
Since the density of water is approximately 1 g/mL, the volume of water needed is 0.1342 mL.
4. Determine the volume of concentrated formic acid needed: To calculate the volume of concentrated formic acid required, we can use the equation:
Volume of concentrated formic acid = Total volume - volume of water
Volume of concentrated formic acid = 1000 mL - 0.1342 mL = 881.7 mL
Therefore, to prepare 90% formic acid, you will need to add 881.7 mL of concentrated formic acid and then make up the volume to 1 L with water.
Your calculations are correct.
To prepare a solution of 90% formic acid from concentrated formic acid, you can follow the steps below:
1. Start by determining the concentration of the concentrated formic acid. In your case, you assume it is 99% pure.
2. Next, calculate the mass of the concentrated formic acid needed. To do this, multiply the volume of the concentrated formic acid by its density.
Mass of concentrated formic acid = Volume of concentrated formic acid × Density of concentrated formic acid
Assuming you want to prepare 1L of the final solution:
Volume of concentrated formic acid = 1L
Density of concentrated formic acid = 1.22 g/ml
Mass of concentrated formic acid = 1L × 1.22 g/ml = 1.22 g
3. Determine the mass of water needed to dilute the concentrated formic acid to the desired concentration of 90%. Subtract the mass of the concentrated formic acid from the total mass of the solution you want to prepare.
Mass of water = Total mass of solution - Mass of concentrated formic acid
Total mass of solution = 1L × 1000 g/L = 1000 g
Mass of water = 1000 g - 1.22 g = 998.78 g
4. Convert the mass of water to volume by dividing it by the density of water (which is approximately 1 g/ml).
Volume of water = Mass of water / Density of water
Volume of water = 998.78 g / 1 g/ml = 998.78 ml
5. To find the volume of concentrated formic acid needed (V), set up an equation using the fact that the mass of formic acid remains constant before and after dilution.
Mass of concentrated formic acid = Mass of diluted formic acid
V × 1.22 g/ml = (1000 - V) × 0.9 g/ml (where 0.9 represents the desired 90% concentration)
6. Solve the equation to find V, which represents the volume of concentrated formic acid needed.
V × 1.22 = (1000 - V) × 0.9
V = (1000 - V) × 0.9 / 1.22
= (900 - 0.9V) / 1.22
= 738.52 - 0.7377V
= 738.52V - 0.7377V²
Rearranging the equation:
0.7377V² - 738.52V + 738.52 = 0
Solve this quadratic equation to find V. In this case, V = 880.90 ml (approx.)
7. Therefore, you would need to add approximately 880.90 ml of the concentrated formic acid and make up the volume to 1L with water to obtain a solution containing 90% formic acid.