3. Choose the hybridization schemes for the following species.
(a) AsBr6−
sp
sp2
sp3
sp3d
sp3d2
(b) CSe2
sp
sp2
sp3
sp3d
sp3d2
(c) PbCl4
sp
sp2
sp3
sp3d
sp3d2
(d) SeO32−
sp
sp3
sp2
sp3d
sp3d2
(e) BiF5
sp
sp2
sp3
sp3d
sp3d2
dfddfefv
To determine the hybridization schemes for the given species, we need to follow a few steps:
Step 1: Determine the central atom in the molecule/ion.
Step 2: Count the number of valence electrons for the central atom.
Step 3: Calculate the number of electron pairs around the central atom.
Step 4: Determine the electron-pair and molecular geometry.
Step 5: Determine the hybridization scheme based on the geometry and the number of electron pairs.
Let's apply these steps to each species:
(a) AsBr6−:
Step 1: The central atom is As (arsenic).
Step 2: Arsenic (As) has 5 valence electrons, and each bromine (Br) contributes one electron (-1 charge).
Total valence electrons: 5 + 6(7) - 1 = 48 e⁻.
Step 3: Considering the number of electron pairs, we divide the valence electrons by 2 since each pair contains 2 electrons.
Number of electron pairs: 48 e⁻ / 2 = 24 electron pairs.
Step 4: The molecular geometry depends on the electron pair arrangement. For AsBr6−, the electron pair arrangement is octahedral, with 6 bonding pairs and no lone pairs.
Step 5: The hybridization scheme is determined by the number of bonding pairs and lone pairs around the central atom. In this case, since there are 6 bonding pairs and no lone pairs, the hybridization is sp3d2.
(b) CSe2:
Step 1: The central atom is C (carbon).
Step 2: Carbon (C) has 4 valence electrons, and each selenium (Se) contributes two electrons.
Total valence electrons: 4 + 2(6) = 16 e⁻.
Step 3: The electron pairs are calculated by dividing the total valence electrons by 2.
Number of electron pairs: 16 e⁻ / 2 = 8 electron pairs.
Step 4: The electron pair arrangement is determined by the molecular geometry. For CSe2, the electron pair arrangement is linear, with 2 bonding pairs and no lone pairs.
Step 5: Since there are 2 bonding pairs and no lone pairs, the hybridization scheme is sp.
(c) PbCl4:
Step 1: The central atom is Pb (lead).
Step 2: Lead (Pb) has 4 valence electrons, and each chlorine (Cl) contributes one electron.
Total valence electrons: 4 + 4(7) = 32 e⁻.
Step 3: The number of electron pairs is obtained by dividing the total valence electrons by 2.
Number of electron pairs: 32 e⁻ / 2 = 16 electron pairs.
Step 4: The electron pair arrangement for PbCl4 is tetrahedral since there are 4 bonding pairs and no lone pairs.
Step 5: The hybridization scheme is determined by the number of bonding pairs and lone pairs. In this case, with 4 bonding pairs and no lone pairs, the hybridization is sp3.
(d) SeO32−:
Step 1: The central atom is Se (selenium).
Step 2: Selenium (Se) has 6 valence electrons, and each oxygen (O) contributes two electrons, along with an extra electron (-2 charge).
Total valence electrons: 6 + 3(6) - 2 = 22 e⁻.
Step 3: The total electron pairs are calculated by dividing the valence electrons by 2.
Number of electron pairs: 22 e⁻ / 2 = 11 electron pairs.
Step 4: The electron pair arrangement for SeO32− is trigonal planar since there are 3 bonding pairs and 1 lone pair.
Step 5: The hybridization scheme is determined by the number of bonding pairs and lone pairs. In this case, with 3 bonding pairs and 1 lone pair, the hybridization is sp3.
(e) BiF5:
Step 1: The central atom is Bi (bismuth).
Step 2: Bismuth (Bi) has 5 valence electrons, and each fluorine (F) contributes one electron.
Total valence electrons: 5 + 5(7) = 40 e⁻.
Step 3: The number of electron pairs is obtained by dividing the total valence electrons by 2.
Number of electron pairs: 40 e⁻ / 2 = 20 electron pairs.
Step 4: The electron pair arrangement for BiF5 is square pyramidal since there are 5 bonding pairs and no lone pairs.
Step 5: The hybridization scheme is determined by the number of bonding pairs and lone pairs. In this case, with 5 bonding pairs and no lone pairs, the hybridization is sp3d2.
So, the final hybridization schemes for the given species are:
(a) AsBr6−: sp3d2
(b) CSe2: sp
(c) PbCl4: sp3
(d) SeO32−: sp3
(e) BiF5: sp3d2