Problem

Which of the following molecules or ions contain …

View

Problem 21 Medium Difficulty

Identify the more polar bond in each of the following pairs of bonds:
(a) HF or HCl
(b) NO or CO
(c) SH or OH
(d) PCl or SCl
(e) CH or NH
(f) SO or PO
(g) CN or NN

Answer

a)
The bond between hydrogen and fluorine in hydrogen fluoride is more polar than that between
hydrogen and chlorine in hydrogen chloride because the difference in electronegativity $(\Delta \mathrm{EN})$
between the two elements in HF $(1.8)$ is more than that in HCl $(1.0)$ .
b)
$\text { The difference in electronegativity ( } \Delta \mathrm{EN})$ between $\mathrm{N}$ and $\mathrm{O}$ is less $(0.4)$ than that between
$\mathrm{C}$ and $\mathrm{O}(0.8)$ and hence $\mathrm{C}-\mathrm{O}$ is more polar than $\mathrm{N}-\mathrm{O}$ bond.
c)
Although oxygen and sulfur are in the same group, oxygen is in second period and sulfur is in
third period. The electronegativity of the elements decreases down the group and hence $\mathrm{O}-\mathrm{H}$
bond is more polar than $\mathrm{S}-\mathrm{H}$ bond. The difference in electronegativity $(\Delta \mathrm{EN})$ for $\mathrm{O}-\mathrm{H}$ bond
$(1.2)$ is more than that for $\mathrm{S}-\mathrm{H}$ bond $(0.4)$
d)
The atomic number of phosphorus is 15 and that of sulfur is 16 . Along the period
electronegativity increases because the size of the atom decreases, as the size increases the
distance between the nucleus and the valence electron decreases. $\mathrm{P}-\mathrm{C} 1$ bond is more polar
than $\mathrm{S}-\mathrm{C} 1$ bond because the electronegativity difference is more for $\mathrm{P}-\mathrm{Cl}(1.0)$ than that for
$\mathrm{S}-\mathrm{Cl}$ bond $(0.6)$
e)
Carbon is group 14 element and nitrogen is group 15 element and hence nitrogen is more
electronegative than carbon. Since nitrogen is more electronegative than carbon the bond
formed between nitrogen and hydrogen will be more polar than the one formed between carbon
and nitrogen. The difference in electronegativity for $\mathrm{N}-\mathrm{H}$ bond $(0.8)$ is more which clearly
shows that $\mathrm{N}-\mathrm{H}$ bond is more polar than $\mathrm{C}-\mathrm{H}$ bond $(0.4)$
f)
$\text { Phosphorus (atomic number }(Z)=15)$ is less electronegative than sulfur $(Z=16)$ and sulfur is
less electronegative than oxygen $(Z=8)$ . Hence the bond formed between $\mathrm{P}$ and $\mathrm{O}$ that is
$\mathrm{P}-\mathrm{O}$ will be more polar compared to that formed between $\mathrm{S}$ and $\mathrm{O}$ that is $\mathrm{S}-\mathrm{O}$ . The
difference in electronegativity $(\Delta \mathrm{EN})$ between $\mathrm{P}$ and $\mathrm{O}$ is 1.2 and that between $\mathrm{S}$ and $\mathrm{O}$ is
0.8
g)
A covalent bond will be polar if there is a difference in the electronegativity between the elements
that form the bond. In other words a covalent bond formed between same elements is always
non-polar while a bond formed between two different elements is polar. Hence $\mathrm{N}-\mathrm{N}$ is non-
polar $(\Delta \mathrm{EN}=0)$ and $\mathrm{C}-\mathrm{N}$ bond is polar $(\Delta \mathrm{EN}=0.4)$ .

Related Courses

Chemistry 101

Chemistry

Chapter 7

Chemical Bonding and Molecular Geometry

Discussion

You must be signed in to discuss.

Top Chemistry 101 Educators

Allea C.

University of Maryland - University College

Watch More Solved Questions in Chapter 7

Problem 1

Problem 2

Problem 3

Problem 4

Problem 5

Problem 6

Problem 7

Problem 8

Problem 9

Problem 10

Problem 11

Problem 12

Problem 13

Problem 14

Problem 15

Problem 16

Problem 17

Problem 18

Problem 19

Problem 20

Problem 21

Problem 22

Problem 23

Problem 24

Problem 25

Problem 26

Problem 27

Problem 28

Problem 29

Problem 30

Problem 31

Problem 32

Problem 33

Problem 34

Problem 35

Problem 36

Problem 37

Problem 38

Problem 39

Problem 40

Problem 41

Problem 42

Problem 43

Problem 44

Problem 45

Problem 46

Problem 47

Problem 48

Problem 49

Problem 50

Problem 51

Problem 52

Problem 53

Problem 54

Problem 55

Problem 56

Problem 57

Problem 58

Problem 59

Problem 60

Problem 61

Problem 62

Problem 63

Problem 64

Problem 65

Problem 66

Problem 67

Problem 68

Problem 69

Problem 70

Problem 71

Problem 72

Problem 73

Problem 74

Problem 75

Problem 76

Problem 77

Problem 78

Problem 79

Problem 80

Problem 81

Problem 82

Problem 83

Problem 84

Problem 85

Problem 86

Problem 87

Problem 88

Problem 89

Problem 90

Problem 91

Problem 92

Problem 93

Problem 94

Problem 95

Problem 96

Problem 97

Problem 98

Problem 99

Problem 100

Problem 101

Problem 102

Problem 103

Problem 104

Problem 105

Problem 106

Problem 107

Problem 108

Problem 109

Problem 110

Problem 111

Problem 112

Problem 113

Problem 114

Problem 115

Problem 116

Video Transcript

so Christians additives mo more four bucks each of the following pairs of bones. Let's see, the 1st 1 is Harry header flooring. So Taylor calculate. Actually, if you don't want actually, what can use a pure act table now here active was quite a useful. You know, the rules lab to ride activities be increasing top to the bottom. Negativity is the craze, so that is useful. And also we can calculate. So be for this one would be four for Florida A and how doom and then calculate the difference. And also same thing. Yeah, actually locate what could Oh, we couldn't use the number. She's more of a basically but could also use if you're at table because the electron activities forklore ing is smaller done for, which means it has a more power. The flooring is more power to track electrons which will make mark you more and it's a part of our So for this question's a sh Oh, well, be more color on the hydrochloride. Be something can use either a pure table out or you want if you want, calculate which is easier for you can do that so naturally in oxygen and carbon oxygen, which so obviously this one will be more color. It's on the rule. So, um, natural while closer or closer to oxygen, compare with vanda carbonate, which is Ah, last polar Obama, is it? If you want technically up, you can do it. But this one is three point menace, riel 0.5. This why would be 3.5 at this point? Do It's well, one. Same thing. I mean, same route the chopper from periodic table because the quicker you don't do a lot of calculations saving people say into the calculation 2.5, subtract 2.1 close to one before and for this one. Well, 2.5 tracked. I'm sorry. Uh, docks. Ages 3.5. Subtract 2.1. He calls to 14 So this is more caller. You can see the hanging can use. Also, use your table as I mentioned before with you know, the rules. You got it. Uh, Esso gas suffer. All right, so it's still do the calculation, which is obviously e calls to for, uh, this one. Will this three subtract 2.5 five? So this will be more Well, er e ch pair was the edge. While it's time quite similar, to be that obviously the way actually fishes a hydrogen has a lord like activity with Sue Calculation your point. Fine. Drag to what? Why was Quinn court? This won't be hair. I shouldn't say it's natural. Yeah, for nine. So this one? No quarter. And we use half. So, um, Pio, Thanks. Go. Oh, it's one. This one of the 3.5. That's track two point y equals 1.4. This is more power. Make sure you can check. I mean, you can try and use the pure at table two softballs problems, and we'll get more familiar is a pure table if you really hate. And CNN compare was an and wealth, I'll be fine, you know, obviously, because those two of the same fix it blades zero and business now. Same. Definitely not, dear. Oh, So the actual number is, uh, when five. Obviously it's ah, more paller

Get More Help with this Textbook