Answer:
a.Low temperature
Explanation
Equation of reaction:
2NO2 <==> N2O4(g) ∆H = +ve
To cause the reaction to become darker brown means to produce more of NO2 gas. That is backward reaction.
Since the reaction is endothermic, decrease in temperature will shift the equilibrium position to the left thereby favouring backward reaction. This is in line with Me Chatelier's principle.
High pressure will rather favour forward reaction (it is not the right option).
That is Magnesium Chloride.
Answer:
their warfare had changed dramatically
Answer:
the answer is 11
Explanation:
Ok, let us understand what is an atomic number, an atomic number is simply the proton number, the atomic number is always seen at the bottom left corner in a element of a periodic table, it is the number of proton in a atom of a certain element.
Given data:
Sublimation of K
K(s) ↔ K(g) ΔH(sub) = 89.0 kj/mol
Ionization energy for K
K(s) → K⁺ + e⁻ IE(K) = 419 Kj/mol
Electron affinity for Cl
Cl(g) + e⁻ → Cl⁻ EA(Cl) = -349 kj/mol
Bond energy for Cl₂
1/2Cl₂ (g) → Cl Bond energy = 243/2 = 121.5 kj/mol
Formation of KCl
K(s) + 1/2Cl₂(g) → KCl(s) ΔHf = -436.5 kJ/mol
<u>To determine:</u>
Lattice energy of KCl
K⁺(g) + Cl⁻(g) → KCl (s) U(KCl) = ?
<u>Explanation:</u>
The enthalpy of formation of KCl can be expressed in terms of the sum of all the above processes, i.e.
ΔHf(KCl) = U(KCl) + ΔH(sub) + IE(K) + 1/2 BE(Cl₂) + EA(Cl)
therefore:
U(KCl) = ΔHf(KCl) - [ΔH(sub) + IE(K) + 1/2 BE(Cl₂) + EA(Cl)]
= -436.5 - [89 + 419 + 243/2 -349] = -717 kJ/mol
Ans: the lattice energy of KCl = -717 kj/mol
