The formation of nitric acid from nitrogen, hydrogen, and oxygen can be written as,
N₂ + H₂ + 3O₂ --> 2HNO₃
The net enthalpy of formation of nitric acid is calculated by,
Hrxn = Hproduct - Hreactant
Since all the reactants are in their elemental forms, the simplified equation would be,
Hrxn = Hproduct
Substituting,
Hrxn = (-186.81 kJ/mol)(2 mols)
<em>Answer: -372.42 kJ</em>
D) + ΔH and +ΔE
Given this is one of the answer choices
Answer:
7,94 minutes
Explanation:
If the descomposition of HBr(gr) into elemental species have a rate constant, then this reaction belongs to a zero-order reaction kinetics, where the r<em>eaction rate does not depend on the concentration of the reactants. </em>
For the zero-order reactions, concentration-time equation can be written as follows:
[A] = - Kt + [Ao]
where:
- [A]: concentration of the reactant A at the <em>t </em>time,
- [A]o: initial concentration of the reactant A,
- K: rate constant,
- t: elapsed time of the reaction
<u>To solve the problem, we just replace our data in the concentration-time equation, and we clear the value of t.</u>
Data:
K = 4.2 ×10−3atm/s,
[A]o=[HBr]o= 2 atm,
[A]=[HBr]=0 atm (all HBr(g) is gone)
<em>We clear the incognita :</em>
[A] = - Kt + [Ao]............. Kt = [Ao] - [A]
t = ([Ao] - [A])/K
<em>We replace the numerical values:</em>
t = (2 atm - 0 atm)/4.2 ×10−3atm/s = 476,19 s = 7,94 minutes
So, we need 7,94 minutes to achieve complete conversion into elements ([HBr]=0).
Answer:
(a) H₃O⁺(aq) + H₂PO₄⁻(aq) ⟶ H₃PO₄(aq) + H₂O(ℓ)
(b) OH⁻(aq) + H₃O⁺(aq) ⟶ 2H₂O(ℓ)
Explanation:
The equation for your buffer equilibrium is:
H₃PO₄(aq) + H₂O(ℓ) ⇌ H₃O⁺(aq)+ H₂PO₄⁻(aq)
(a) Adding H₃O⁺
The hydronium ions react with the basic dihydrogen phosphate ions.
H₃O⁺(aq) + H₂PO₄⁻(aq) ⟶ H₃PO₄(aq) + H₂O(ℓ)
(b) Adding OH⁻
The OH⁻ ions react with the more acidic hydronium ions.
OH⁻(aq) + H₃O⁺(aq) ⟶ 2H₂O(ℓ)
Answer:
343.98 nm is the longest wavelength of radiation with enough energy to break carbon–carbon bonds.
Explanation:
A typical carbon–carbon bond requires 348 kJ/mol=348000 J/mol
Energy required to breakl sigle C-C bond:E
where,
E = energy of photon
h = Planck's constant = 
c = speed of light = 
= wavelength of the radiation
Now put all the given values in the above formula, we get the energy of the photons.
343.98 nm is the longest wavelength of radiation with enough energy to break carbon–carbon bonds.
