Answer:
ΔH°f P4O10(s) = - 3115.795 KJ/mol
Explanation:
- P4O10(s) + 6H2O(l) ↔ 4H3PO4(aq)
- ΔH°rxn = ∑νiΔH°fi
∴ ΔH°rxn = - 327.2 KJ
∴ ΔH°f H2O(l) = - 285.84 KJ/mol
∴ ΔH°F H3PO4(aq) = - 1289.5088 KJ/mol
⇒ ΔH°rxn = (4)(- 1289.5088) - (6)(- 285.84) - ΔH°f P4O10(s) = - 327.2 KJ
⇒ ΔH°f P4O10(s) = - 5158.035 + 1715.04 + 327.2
⇒ ΔH°f P4O10(s) = - 3115.795 KJ/mol
Attraction between a cation in one element and an anion in the other element
We can calculate for temperature by assuming the equation
for ideal gas law:
P V = n R T
Where,
P = pressure = 1.80 atm
V = volume = 18.2 L
n = number of moles = 1.20 moles
R = gas constant = 0.08205746 L atm / mol K
Substituting to the given equation:
T = P V / n R
T = (1.8 atm * 18.2 L) / (1.2 moles * 0.08205746 L atm /
mol K)
T = 332.70 K
We can convert K unit to ˚C unit by subtracting 273.15
to Kelvin, therefore
T = 59.55 ˚<span>C</span>
