FeSO₄*7H₂O(s) = FeSO₄(s) + 7H₂O(g)
M(FeSO₄*7H₂O)=278.0 g/mol
M(FeSO₄)=151.9 g/mol
m(FeSO₄*7H₂O)/M(FeSO₄*7H₂O)=m(FeSO₄)/M(FeSO₄)
m(FeSO₄)=M(FeSO₄)m(FeSO₄*7H₂O)/M(FeSO₄*7H₂O)
m(FeSO₄)=151.9*100.0/278.0=54.6 g
m(FeSO₄)=54.6 g
The total energy can be found by adding the different energies:
628 + 15,600 + 712
= 16.94 kJ
Explanation:
From the source, The student recrystallized biphenyl by using benzene. Biphenyl is non polar and so is benzene. Biphenyl is very soluble in benzene at low as well as high temperature. Thus, it do not recrystallize as like dissolves like and gives a very poor yield.
The good recovery of the product is dependent on compound having high solubility at the high temperatures and having low solubility at the low temperatures.
Pure water does
not have enough ions to conduct electricity. A mixture of metals such as iron,
zinc and copper in the wet soil can trigger electrolysis that requires excess
energy in the form of over potential to conduct electricity. The excess energy
is needed due to limited self-ionization of water. The wet soil then can
conduct current when positive and negative ions are present. The water ions begin
to flow from anode (positive electrode) to cathode (negative electrode) to be oxidize
and produce electricity.
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The moles of potassium that you would need to prepare 1200 g of 5% potassium sulfate solution is 1.538 moles
calculation
calculate the mass potassium using the below formula
%M/M = mass of the solute(potassium)/mass of the solvent (potassium sulfate solution)
let the mass of potassium be represented by Y
then convert % into fraction = 5/100
5/100 = Y/1200
cross multiplication
100y = 6000
divide both side by 100
Y= 60 g
moles of potassium =mass/molar mass
= 60/39=1.538
