Chemistry

posted by .

A 1.42-g sample of a pure compound, with formula M2SO4, was dissolved in water and treated with an excess of aqueous calcium chloride, resulting in the precipitation of all the sulphate ions as calcium sulphate. The precipitate was collected, dried, and found to weigh 1.36 g. Determine the atomic mass of M, and identify M.

Please explain!

  • Chemistry -

    ..........M2SO4 + CaCl2 --> CaSO4 + 2MCl
    initial....1.42g....0........0........0
    add................xs..........
    change.......................1.36
    equil......0..................1.36
    moles CaSO4 = 136/molar mass CaSO4.
    moles M2SO4 = moles CaSO4 (1 mole CaSO4 came from 1 mole M2SO4.)
    moles M2SO4 = grams/molar mass. You know moles from above and grams from the problem, solve for molar mass.
    Now that you know the molar mass of M2SO4, subtract 96 (due to the SO4) to leave 2 M^+, then divide by 2 to obtain M. You can look on the periodic table to identify M.

  • Chemistry -

    Atomic mass of the M is 23 g/mol
    So M is actually Sodium (Na)

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. chemistry

    problem 2. a sample of calcium chloride weighs 1.64g. it is dissolved in water and silver nitrate solution added.a precipitate of silver chloride weighing 4.24g was formed.determine the percentage composition of each element. the simple …
  2. ap chem

    A 1.42 g. sample of a pure compound, with formula M2SO4, was dissolved in water and treated with and excess of aqueous barium chloride, resulting in the precipitation of all the sulfate ions as barium sulfate. The precipitate was collected, …
  3. Gen Chemistry

    52.8 mL of a calcium chloride solution with unknown concentration was treated with phosphoric acid to remove all of the calcium ions in the form of a precipitate. The precipitate was filtered, dried and was found to have the mass of …
  4. Chemistry

    2NaF + CaCl2 ¨ CaF2 + 2NaCl An excess of 0.20 M NaF is used to precipitate the calcium ions from a 50.0 mL sample of a calcium chloride solution. What is the concentration of the original calcium chloride solution?
  5. Chemistry

    A 0.5370 g sample of a pure soluble chloride compound is dissolved in water, and all of the chloride ion is precipitated as AgCl by the addition of an excess of silver nitrate. The mass of the resulting AgCl is found to be 1.2523 g. …
  6. chemistry

    A 0.5917 g sample of a pure soluble chloride compound is dissolved in water, and all of the chloride ion is precipitated as AgCl by the addition of an excess of silver nitrate. The mass of the resulting AgCl is found to be 1.5683 g. …
  7. chemistry

    A 25.0 mL sample of drinking water suspected to contain lead(II) ions is treated with excess 0.800 M sodium chloride. A precipitate forms, which is filtered, dried, and weighed. 1.36 g of precipitate are collected. What was the concentration …
  8. chemistry 20

    A student mixed a solution of aqueous calcium chloride with an aqueous solution of magnesium sulphate. A precipitate formed. 1) Write the balance chemical equation for the reaction including states of matter. Ensure you write the reactants …
  9. Chem

    A tablet containing calcium carbonate and fillers with a mass of 1.631 g was dissolved in HCl. After the fillers were filtered out, the HCl was neutralized by adding sodium carbonate. The resulting precipitate was pure calcium carbonate …
  10. Chemistry

    A tablet containing calcium carbonate and fillers with a mass of 1.631 g was dissolved in HCl. After the fillers were filtered out, the HCl was neutralized by adding sodium carbonate. The resulting precipitate was pure calcium carbonate …

More Similar Questions