(a)
Interpretation:
The two-particle coulombic energy of attraction is to be compared with more precise calculation of the lattice energy for the given ionic crystal.
Concept introduction:
The amount of energy released when one formula unit moles of oppositely charged gaseous ions binds together to form a crystal is known as the lattice energy. The value of lattice energy is negative. It is used as a measure for stability of a crystal.
Answer to Problem 21.52E
The two-particle coulombic energy of attraction is
Explanation of Solution
According to Coulomb’s law the potential energy of two oppositely charged particles that are
Where,
•
•
The closed distance between the opposite ions is calculated by considering the Table 21.4. The radii of
Thus, the closest distance between the opposite ions is
Substitute the values of charge on electron, permittivity of space and distance between two ions in equation (1).
For one mole of ions, the energy is multiplied by Avogadro number as shown below.
Thus, the two-particle coulombic energy of attraction is
The lattice energy is given by the expression as shown below.
Where,
•
•
•
•
•
•
•
From the Table 21.6, the value of
The
Substitute value of
Thus, the calculated lattice energy is
Therefore, the magnitude of two-particle coulombic energy of attraction is less than the lattice energy.
The two-particle coulombic energy of attraction is
(b)
Interpretation:
The two-particle coulombic energy of attraction is to be compared with more precise calculation of the lattice energy for the given ionic crystal.
Concept introduction:
The amount of energy released when one formula unit moles of oppositely charged gaseous ions binds together to form a crystal is known as the Lattice energy. The value of lattice energy is negative. It is used as the measure for stability of a crystal.
Answer to Problem 21.52E
The two-particle coulombic energy of attraction is
Explanation of Solution
According to Coulomb’s law the potential energy of two oppositely charged particles that are
Where,
•
•
The closed distance between the opposite ions is calculated by considering the Table 21.4. The radii of
Thus, the closest distance between the opposite ions is
Substitute the values of charge on electron, permittivity of space and distance between two ions in equation (1).
For one mole of ions, the energy is multiplied by Avogadro number as shown below.
Thus, the two-particle coulombic energy of attraction is
The lattice energy is given by the expression as shown below.
Where,
•
•
•
•
•
•
•
From the Table 21.6, the value of
Substitute value of
Thus, the calculated lattice energy is
Therefore, the magnitude of two-particle coulombic energy of attraction is less than the lattice energy.
The two-particle coulombic energy of attraction is
(c)
Interpretation:
The two-particle coulombic energy of attraction is to be compared with more precise calculation of the lattice energy for the given ionic crystal.
Concept introduction:
The amount of energy released when one formula unit moles of oppositely charged gaseous ions binds together to form a crystal is known as the Lattice energy. The value of lattice energy is negative. It is used as the measure for stability of a crystal.
Answer to Problem 21.52E
The two-particle coulombic energy of attraction is
Explanation of Solution
According to Coulomb’s law the potential energy of two oppositely charged particles that are
Where,
•
•
The closed distance between the opposite ions is calculated by considering the Table 21.4. The radii of
Thus, the closest distance between the opposite ions is
Substitute the values of charge on electron, permittivity of space and distance between two ions in equation (1).
For one mole of ions, the energy is multiplied by Avogadro number as shown below.
Thus, the two-particle coulombic energy of attraction is
The lattice energy is given by the expression as shown below.
Where,
•
•
•
•
•
•
•
From the Table 21.6, the value of
Substitute value of
Thus, the calculated lattice energy is
Therefore, the magnitude of two-particle coulombic energy of attraction is less than the lattice energy.
The two-particle coulombic energy of attraction is
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Chapter 21 Solutions
Physical Chemistry
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