How do I prepare 250ml of 10% phosphoric acid from 85% phosphoric acid(density 1.69g/ml)?
Thanks.
how i prepare 0.5% phosphoric acid from 65% of phospheric acid
To prepare 250ml of a 10% phosphoric acid solution from 85% phosphoric acid, you need to dilute the concentrated acid with water. Here are the step-by-step instructions:
Step 1: Calculate the amount of concentrated acid needed.
Since the concentration of the concentrated acid is 85%, you can use the following formula to calculate the volume of acid needed:
Volume of concentrated acid = (Volume of diluted acid x Desired concentration of diluted acid) / Concentration of concentrated acid
In this case, the desired volume of diluted acid is 250 ml, the desired concentration is 10%, and the concentration of the concentrated acid is 85%. Plugging these values into the formula:
Volume of concentrated acid = (250 ml x 0.10) / 0.85
Step 2: Calculate the mass of concentrated acid needed.
To calculate the mass of the concentrated acid needed, you can use the following formula:
Mass of concentrated acid = Volume of concentrated acid x Density of concentrated acid
The density of the concentrated acid is given as 1.69 g/ml. Plugging in the value from step 1:
Mass of concentrated acid = (Volume of concentrated acid) x (Density of concentrated acid)
= (Volume of concentrated acid) x (1.69 g/ml)
Step 3: Calculate the volume of water needed.
To find the volume of water needed, subtract the volume of concentrated acid from the desired total volume:
Volume of water = Desired total volume - Volume of concentrated acid
= 250 ml - (Volume of concentrated acid)
Step 4: Prepare the diluted solution.
Using a clean container, add the calculated volume of concentrated phosphoric acid obtained in step 1 to the container. Then, add the calculated volume of water from step 3 to the container. Mix the solution thoroughly to ensure the acid and water are well combined.
By following these steps, you should be able to prepare 250ml of a 10% phosphoric acid solution using 85% phosphoric acid.
To prepare 250ml of a 10% phosphoric acid solution, you will need to calculate the amount of 85% phosphoric acid required and then dilute it accordingly. Here's how you can do it:
Step 1: Calculate the amount of pure phosphoric acid in the final solution.
To calculate the amount of pure phosphoric acid needed, you can use the equation:
(Amount of pure acid / Total volume of solution) x 100 = Desired concentration
Therefore, let x be the amount of pure phosphoric acid needed. The equation can be rearranged as:
(x g / 250 mL) x 100 = 10%
Simplifying the equation:
(x / 250) x 100 = 10
Multiply both sides by 250 and divide by 100:
x = (10 x 250) / 100
x = 25 g
So, you will need 25 g of pure phosphoric acid.
Step 2: Calculate the volume of the 85% phosphoric acid.
To calculate the volume of 85% phosphoric acid, we can use the equation:
Volume (ml) = Mass (g) / Density (g/ml)
In this case, the density of the 85% phosphoric acid is given as 1.69 g/ml. Therefore:
Volume = 25 g / 1.69 g/ml
Volume ≈ 14.8 ml (rounded to one decimal place)
So, you will need approximately 14.8 ml of 85% phosphoric acid.
Step 3: Dilute the 14.8 ml of 85% phosphoric acid.
To do this, add the 14.8 ml of 85% phosphoric acid to a container and then add distilled water to bring the total volume to 250 ml. Mix it well to ensure uniformity.
By following these steps, you will have prepared 250 ml of a 10% phosphoric acid solution from 85% phosphoric acid.
Minnie, you don't mention if this is percent by mass or percent by volume.For the moment, I will assume this is 85% H3PO4 by mass with a density of 1.69 g/mL.
Work by mass.
85 g/100 g soln is 85% by mass = 0.85 g/g soln.
We want 25 g/250 g soln for 10%
(85 g/100 g soln) x ?? g soln = 25 g and solve for ??g. That gives me 29.41 g of the soln. Weigh out 29.41 g of that soln, add water to make to a total mass of 250 g (i.e., add 220.6 g H2O) and you will have 25 g H3PO4/250 g soln which is 10%. Let me caution you, however, that this will NOT be 250 mL volume but somewhat less than that depending upon the density of the 10% solution.
If you want to do it by volume, then
100 g soln with a density of 1.69 occupies a volume of 100/1.69 = 59.17 mL or 85/59.17 = 1.4365 g/mL.
Then 1.4365 mL x ?? mL = 25 g
??Ml = 25/1.4365 = 17.4 mL. Therefore, pipet 17.4 mL of the 85% soln into the flask and add water to make 250. That will give you 250 mL of a 10% w/v solution.