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[H+] = [ ? ] x 10!?)
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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
To determine:
Lattice energy of KCl
K⁺(g) + Cl⁻(g) → KCl (s) U(KCl) = ?
Explanation:
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
The lattice energy of KCl is calculated using the Born-Haber cycle by considering the energies of several steps including the sublimation of potassium, ionization of potassium, dissociation of Cl bond, electron affinity of Cl, and formation of KCl. The given values are plugged into a formula resulting in a lattice energy of -718 kJ/mol.
To calculate the lattice energy of KCl using the Born-Haber cycle, we need to follow several thermochemical steps. The steps include, first sublimation of potassium, the ionization of potassium, bond dissociation enthalpy to produce Cl, the electron affinity of Cl, and formation of KCl (s). Combining energy changes associated with all these steps would give us energy change for the formation of KCl from individual K and Cl2, it is called as enthalpy of formation (ΔH°f) for KCl.
Using the given values for each step, we use the formula: ΔH°f = ΔHsub + IE1 + 1/2* DCl2 - EA1 + lattice energy.
Substituting the given values, -436.5 = 89 + 419 + 1/2*243 -349 + lattice energy. Solving gives the lattice energy as -718 kJ/mol.
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B. Mechanical- is NOT a type of adaptation
(K) potassium is the metal that will react most readily with 1.0 M HCl to produce H2(g).
Potassium is a silvery-white metal with the symbol K and atomic number 19.
The reaction will be
The potassium will react with HCl to produce potassium chloride and hydrogen gas.
It is a single displacement reaction.
In this type of reaction, more reactive metal is displaced with less reactive metal.
Thus, the correct option is 2) K.
Learn more about potassium, here:
Answer: The correct answer is Option 2.
Explanation:
The reaction between a metal and HCl is a type of single displacement reaction.
Single replacement reactions are defined as the reactions in which more reactive metal replaces less reactive metal from its chemical equation. The reactivity is determined from the series called reactivity series. The metal lying above in the series is more reactive than the metal lying below in the series.
General equation for these types of reactions is:
From the series attached below, the most reactive metal is Potassium (K).
Increasing order of the reactivity of metals are:
Hence, the correct answer is Option 2.
Answer: Option (3) is the correct answer.
Explanation:
In the process of oxidation, an atom loses electrons or an increase in oxidation number of the atom occurs.
For example, is an oxidation process.
Whereas in a process of reduction, an atom gain electrons or a decrease in oxidation number of the atom occurs.
For example, is a reduction process.
Thus, we can conclude that the chemical process in which electrons are gained by an atom or an ion is called reduction.