1. Questions

chemistry-help needed

How do I prepare 250ml of 10% phosphoric acid from 85% phosphoric acid(density 1.69g/ml)?
Thanks.

  1. 👍
  2. 👎
  3. 👁
Minnie

  1. 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.

    1. 👍
    2. 👎
    DrBob222

  2. how i prepare 0.5% phosphoric acid from 65% of phospheric acid

    1. 👍
    2. 👎
    Anonymous

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.300 M phosphoric acid solution. kPa1: 2.16 kPa2: 7.21

  2. Science

    Concentrated phosphoric acid is 90% by mass and the remaining mass is water.The molarity of phosphoric acid in 90% is 12.2M at rtp. a)What is the density of the solution at rtp ? b)What volume (in mL)of this solution is needed to

  3. AP CHEMISTRY

    Phosphoric acid is triprotic acid (three ionizable hydrogens). The values of its stepwise ionization constants are Ka1= 7.5E-5, Ka2= 6.2E-8, and Ka3= 4.2E-13 1) Write the chemical equation for the first ionization reaction of

  4. Chemistry

    how to prepare and calculate 10%,20% and 30% of phosphoric acid from the concentrated? Meaning that if 10% = 10%phosporic acid+90% of water. let say i want to prepare in volume of 250ml. given, Formula: H3PO4 Melting point: 42.35

  1. Chemistry

    Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.300 M phosphoric acid solution. pKa1: 2.16 pKa2: 7.21

  2. general chemistry II

    Phosphoric Acid is usually obtained at an 85% phosphoric acid solution, by mass. If this solution is 15 M, what is the density of the solution? What is its MOLALITY?

  3. chemistry

    Calcium carbonate reacts with phosphoric acid to produce calcium phosphate, carbon dioxide, and water. 3 CaCO3(s) + 2 H3PO4(aq) Ca3(PO4)2(aq) + 3 CO2(g) + 3 H2O(l) How many grams of phosphoric acid react with excess calcium

  4. chemistry

    Calculate the molarity of a phosphoric acid(H3PO3)solution that is 84% by mass phosphoric acid and has a density of 1.87g/mL.?

  1. chemistry

    Phosphoric acid is a triprotic acid, so H3PO4, H2PO4 -, and HPO4 2- are all acids. Which of the solutions below would have the lowest pH? 0.1 M NaH2PO4 0.1 M Na2HPO4 0.1 M Na3PO4

  2. Chemistry

    How do I prepare 10% ortho-phosphoric acid in 250ml volumetric flask from 85% ortho-phosphoric acid(density 1.69g/ml) ?

  3. chem

    Cola contains H3PO4. In order to determine the concentration of phosphoric acid in 50.0 mL of cola, a precipitation reaction with excess silver nitrate was carried out. The product, silver phosphate, was dried and found to weigh

  4. Chemistry 20

    What volume of concentrated phosphoric acid is required to prepare 250ml of a 0.375mol/L solutions?

You can view more similar questions or ask a new question.