Answer:
The answer to your question is MgSO₄ 5H₂O
Explanation:
Data
mass of MgSO₄ = 2.86 g
mass of H₂O = 2.14 g (5 - 2.86)
Process
1.- Calculate the molecular mass of the compounds
MgSO₄ = 24 + 32 + (16 x 4) = 120
H₂O = 16 + 2 = 18
2.- Convert the grams obtain to moles
120 g of MgSO₄ --------------- 1 mol
2.8 g ---------------- x
x = (2.8 x 1)/120
x = 0.024 moles
18 g of H₂O --------------------- 1 mol
2.14 g -------------------- x
x = (2.14 x 1)/18
x = 0.119
3.- Divide by the lowest number of moles
MgSO₄ = 0.024/0.024 = 1
H₂O = 0.119/ 0.024 = 5
4.- Write the molecular formula
MgSO₄5H₂O
The metal conducts the heat and through conduction, cooks the brownies; conduction also cooks the brownies in the glass pan, but since infrared goes right through the glass, they also cook by radiation.
Answer:
ΔG°rxn = +50.8 kJ/mol
Explanation:
It is possible to obtain ΔG°rxn of a reaction at certain temperature from ΔH°rxn and S°rxn, thus:
<em>ΔG°rxn = ΔH°rxn - T×S°rxn (1)</em>
In the reaction:
2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l)
ΔH°rxn = 3×ΔHfNO2 + ΔHfH2O - (2×ΔHfHNO3 + ΔHfNO)
ΔH°rxn = 3×33.2kJ/mol + (-285.8kJ/mol) - (2×-207.0kJ/mol + 91.3kJ/mol)}
ΔH°rxn = 136.5kJ/mol
And S°:
S°rxn = 3×S°NO2 + S°H2O - (2×S°HNO3 + S°NO)
ΔH°rxn = 3×0.2401kJ/molK + (0.0700kJ/molK) - (2×0.146kJ/molK + 0.2108kJ/molK)
ΔH°rxn = 0.2875kJ/molK
And replacing in (1) at 298K:
ΔG°rxn = 136.5kJ/mol - 298K×0.2875kJ/molK
<em>ΔG°rxn = +50.8 kJ/mol</em>
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Molar mass of LiBr (mm )= 86.845 g/mol
Molarity ( M ) = 4 M
Mass of solute ( m ) = 100 g
Volume ( V ) = in liters ?
V = m / mm * M
V = 100 / 86.845 * 4
V = 100 / 347.38
V = 0.2875 L
hope this helps!.
