Answer:
-252.5 kJ/mol = ΔH H2O(g)
Explanation:
ΔH Fe2O3 = -825.5kJ/mol
ΔH H2 = 0kJ/mol
ΔH Fe = 0kJ/mol
Based on Hess's law, ΔH of a reaction is the sum of ΔH of products - ΔH of reactants. For the reaction:
Fe2O3(s) + 3 H2(g) →2Fe(s) + 3 H2O(g)
ΔHr = 67.9kJ/mol = 3*ΔH H2O + 2*ΔHFe - (ΔH Fe2O3 + 3*Δ H2)
67.9kJ/mol = 3*ΔH H2O + 2*0kJ/mol - (ΔH -825.5kJ/mol + 3*Δ H2)
67.9 = 3*ΔH H2O(g) + 825.5kJ/mol
-757.6kJ/mol = 3*ΔH H2O(g)
<h3>-252.5 kJ/mol = ΔH H2O(g)</h3>
Then you will multiply the number of moles by 6.022×1023formula units/mol . To determine the molar mass of a compound, add the atomic weight on the periodic table in g/mol times each element's subscript. Since the formula unit CaO has no subscripts, they are understood to be 1
Answer is: at lower temperatures the reaction rate would decrease.
The lower is the temperature, the slower the reaction becomes.
The Haber process is procedure for the production of ammonia, in this process atmospheric nitrogen (N₂) is converted to ammonia (NH₃):
N₂ + 3H₂ ⇄ 2NH₃ ΔrH = -92 kJ/mol.
Because this is exothermic reaction (enthalpy is less than zero), at lower temperatures, the equilibrium is in favor of ammonia, but the reaction doesn't proceed at a detectable rate.
Answer:
pH of the buffer is 10.10
Explanation:
trimethylamine is a weak base that, in presence with its conjugate base, trimethylammonium ion, produce a buffer.
To determine the pH of the buffer we use H-H equation for weak bases:
pOH = pKb + log [Conjugate acid] / [Weak base]
<em>pKb is -log Kb = 4.20</em>
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pOH = 4.20 + log [N(CH₃)₃] / [NH(CH₃)₃]
Replacing the concentrations of the problem:
pOH = 4.20 + log [0.20M] / [0.40M]
pOH = 3.90
As pH = 14 -pOH
<h3>pH of the buffer is 10.10</h3>
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