Question

38.02 gram sample of a hydrate of MnSO4 was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, 20.72 grams of the anhydrous compound remained. What is the formula of the hydrate?

Answer 1

MnSO4 *7H2O

Step-by-step explanation:

Total mass of water and Magnesium sulfate 38.02

Mass of anhydrous - 20.72

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Mass of water 17.3

20.72g MnSO4 *
`(1 mol MnSO4)/(151 g MnSO4)` = 0.137 mol MnSO4

17.3g H2O*
`(1 mol H2O)/(18 g H2O)` = .961 mol H2O

`(.961 mol H2O)/(.137 mol MnSO4)` ≈ 7 mol H20 for every 1 mol MnSo4