Unit 2.04 - 2.05

Question 1

When drawing a Lewis Structure, what does it involve?

Answer 1

It involves multiple bonds, it may be possible to draw a number of different Lewis Structures.

Question 2

What do we call those different versions of a Lewis Structure?

Answer 2

Resonance structures

Question 3

Why are bonds in a resonance structure the same length?

Answer 3

Because the structure is an “average” of all 3 possible resonance structures and each bond is really one and one third covalent bonds rather than any combination of two singles and one double.

Question 4

What is the evidence for the “one and one third” bond order?

Answer 4

That all bounds are found to be the same length.

Question 5

Define Isomer

Answer 5

Same number of TYPES OF ATOMS but bonded differently (different arrangement)

Question 6

Define Resonance

Answer 6

Getting to choose the bond order

Question 7

Define Formal Charge

Answer 7

Tells us where the charge is located; to determine a more accurate structure of molecules

Question 8

What do we want the most electronegative atom to have when it comes to formal charge?

Answer 8

The most negative formal charge

Question 9

Going from left to right on the periodic table, electronegativity…

Answer 9

increases

Question 10

Going from top to bottom on the periodic table, electronegativity…

Answer 10

decreases

Question 11

When there is an ion charge present, what rule applies to the formal charge

Answer 11

The formal charge adds up to the overall charge

Question 12

Every time you have a single bond,…

Answer 12

its a sigma bond

Question 13

Every time you have a double bond,…

Answer 13

One line is a sigma bond and the other is a pi bond

Question 14

Every time you have a triple bond,..

Answer 14

there is one sigma bond and two pi bonds

Question 15

Define local

Answer 15

Electrons in one area or a particular area

Question 16

Define delocal

Answer 16

Electrons that don’t stay in their area; able to freely move around

Question 17

Sigma bond is when…

Answer 17

There is a simple end on end (head to head overlap; cloud density is located along the axis of the bond

Question 18

Pi bond is when…

Answer 18

When the bonds are parallel of each other; cloud density is located above and below axis of the bond

Question 19

Whenever a double or triple covalent bond is formed with the central atom, what is considered a sigma bond?

Answer 19

the first (and strongest) bond

Question 20

Whenever a double or trile covalent bond is formed with the central atom, what are the other (not first) bonds considered as?

Answer 20

pi bonds

Question 21

What do pi bonds lead to?

Answer 21

They lead to delocalized electron clouds, giving rise to the potential for some electron movement

Question 22

What is the difference between sigma and pi bonds when it comes to electron movement?

Answer 22

Sigma bonds can freely rotate, but pi bonds in alkenes prevent the rotation

Question 23

Define alloy

Answer 23

a mixture of metals

Question 24

Define density in atoms

Answer 24

The more atoms packed in molecule, leaving little space behind, the more dense it is

Question 25

What are the properties of interstitial alloys?

Answer 25

They are less malleable (the ability to bend) and ductile and typically more dense.

Question 26

Define Interstitial alloys

Answer 26

They have a structure of big metal atoms and smaller metal atoms in between.