Answer:
Absorbed
Released
Released
Explanation:
The formation of a cation is an endothermic process because energy must be absorbed in order to remove an electron from an atom.
Similarly, energy is evolved when an electron is added to an atom to form a negative ion.
The formation of an ionic compound is an exothermic process. Since ionic compounds are more stable than the individual ions separated by a distance, the excess energy of the isolated ions is evolved when the ionic compound is formed.
Answer:
SeCl₆ < SeF₂ < SeO₂
Explanation:
To determine the order of the bond angle of the compound, we need to determine the hybridization of each compound given.
For:
SeO₂, The hybridization is sp² because the Se is doubly bonded to O at both sides and Se contains a lone pair of electrons.
SeCl₆, Se is attached to six different Cl atoms via a single bond in a hexagonal shape. Thus, SeCl₆ hybridization is sp³d²
SeF₂, Here, Se is singly bonded to F atoms on both sides and Se contains a lone pair of electrons. The hybridization is sp³
Therefore, the bond angle in sp² = 120°, sp³ = 109.8°, sp³d² = 90°
Hence, the order is: SeCl₆ < SeF₂ < SeO₂
Answer:
3.011 × 10²³ atoms of Al
Explanation:
Given data:
Number of moles of Al₂(SO₄)₃ = 0.25 mol
Number of atoms of Al = ?
Solution:
In one mole of Al₂(SO₄)₃ there are 2 moles of Al.
In 0.25 mol × 2 = 0.5 mol
1 mole of any substance contain 6.022 × 10²³ atoms.
In 0.5 moles of Al:
1 mole contain 6.022 × 10²³ atoms.
0.5 mol × 6.022 × 10²³ atoms/ 1 mol
3.011 × 10²³ atoms
