chemistry

posted by .

A 2.50 g sample of a hydrate of calcium sulphate losses 0.523 g of water when heated. Determine the mass percent of water in the hydrate and the formula of the hydrate.

  • chemistry -

    CaSO4.XH2O

    find the mole ratio of water to CaSO4.

    moleswater=.523/18
    molesCaSO4=(2.5-.523)/molmassCaSO4

    divide moles water by the moles CaSO4, that is X

  • chemistry -

    percent water = (mass H2O/mass sample)*100= (0.523/2.50)*100 = 20.92 which I would round to 20.9%.

    To find the formula, take a 100 gram sample which provides
    20.9 g H2O
    100-20.9 = 79.1 g CaSO4

    moles water = 20.9/18 = 1.16
    moles CaSO4 = 79.1/136 = 0.582
    Now find the ratio of water to 1 atom of the CaSO4. The easy way to do that is to divide 0.582 by 0.582 = 1.0000 CaSO4
    Then 1.16/0.582 = ?? H2O

  • chemistry -

    I believe it comes out to CaSO4 x 2H20

    20.9%

    2:1 ratio

    I think haha

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. chem

    a 2.50g sample of hydrate of calcium sulfate losses 0.523g of water when heated. what is the mass percent of water in the hydrate and the formula for the hydrate difference of the two masses divided by the initial mass. I believe Adam …
  2. chemistry

    In the experiment, a hydrate is heated to form an anhydrate. The masses of the before and after are measured and the percent of the water in the hydrate is calculated. If some of the hydrate spatters out of the crucible and isnt noticed, …
  3. chemistry

    A 2.500 gram sample of hydrate of calcium sulfate loses 0.532 grams of water when heated. Determine the mass percent of water in the hydrate and the formula of the hydrate.
  4. Chemistry

    A 32.907-g sample of a hydrate of Au (CN)3 contains 5.406 g H2O What is the formula for the hydrate?
  5. chemistry

    I need help with this lab. Write the equation for the decomposition of the hydrate, CuSO4*XH2O. Mass of crucible and hydrate: 93.000g Mass of crucible and pure salt: 91.196g I need to calculate the following: 1. mass of water in hydrate …
  6. Chemistry

    I need help with this lab. Write the equation for the decomposition of the hydrate, CuSO4*XH2O. Mass of crucible and hydrate: 93.000g Mass of crucible and pure salt: 91.196g I need to calculate the following: 1. mass of water in hydrate …
  7. chemistry

    Cobalt(2) chloride is commonly obtained from chemical supply houses as a hydrate with the formula COCL2*6H2O an analysis showed that 25.0 g of this hydrate contains 11.3 g of water what is the percent water by weight in this hydrate?
  8. Chemistry

    Experiment 1 results: mass of crucible 88g mass of hydrate 93g mass of salt 91.196g 1. Calculate the following: a:mass of water in the hydrate sample (g) b:number of moles of water in the sample c:mass of pure salt in the sample (g) …
  9. Chemistry

    7. A student conducts an experiment on a different hydrate. The empty crucible is heated to a constant mass of 24.330. A sample of the unidentified hydrate is placed in the crucible, and the total mass is 31.571 g. The crucible and …
  10. Chemistry

    A hydrate of copper (II) sulfate with formula CuSO4.xH2O has a molar mass of 250.0 g/mol. 2.545 g of hydrate is heated and 63.85% of the residue is found after heating. a) Determine the value of x in the formula of the compound b) …

More Similar Questions