Answer:
MgSO4.7H2O
Explanation:
Let the formula for the hydrated magnesium sulphate be MgSO4.xH2O
Mass of the hydrated salt (MgSO4.xH2O) = 12.845g
Mass of anhydrous salt (MgSO4) = 6.273g
Mass of water molecule(xH2O) = Mass of the hydrated salt — Mass of anhydrous salt = 12.845 — 6.273 = 6.572g
Now,we can obtain the number of mole of water molecule present in the hydrated salt as follows:
Molar Mass of hydrated salt (MgSO4.xH2O) = 24 + 32 + (16x4) + x(2 + 16) = 24 + 32 + 64 + x(18) = 120 + 18x
Mass of xH2O/ Molar Mass of MgSO4.xH2O = Mass of water / mass of hydrated salt
18x/120 + 18x = 6.572/12.845
Cross multiply to express in linear form
18x x 12.845 = 6.572(120 + 18x)
231.21x = 788.64 + 118.296x
Collect like terms
231.21x — 118.296x = 788.64
112.914x = 788.64
Divide both side by 112.914
x = 788.64 /112.914
x = 7
Therefore the formula for the hydrated salt (MgSO4.xH2O) is MgSO4.7H2O
Do we get multiple choice
there are 4 atoms in aluminum chloride
Answer:
1. Dmitri Mendeleev
2. Johann Dobhereiner
3. John Newlands
4. Henry Moseley
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Answer:
The percentage yield of O2 is 66.7%
Explanation:
Reaction for decomposition of potassium chlorate is:
2KClO₃ → 2KCl + 3O₂
The products are potassium chloride and oxygen.
Let's find out the moles of chlorate.
Mass / Molar mass = Moles
12.3 g / 123 g/mol = 0.1 mol
So ratio is 2:3, 2 moles of chlorate produce 3 mol of oxygen.
Then, 0.1 mol of chlorate may produce (0.1 .3)/ 2 = 0.15 moles
Let's convert the moles of produced oxygen, as to find out the theoretical yield.
0.15 mol . 32 g/ 1mol = 4.8 g
To calculate the percentage yield, the formula is
(Produced Yield / Theoretical yield) . 100 =
(3.2g / 4.8g) . 100 = 66.7 %