T1- p Block LP5

Question 1

What are oxyacids?

Answer 1

Acids in the form of O_mE(OH)_n where E is p block compound

Question 2

Using Pauling rules, what is pK_a of oxyacids in water?

Answer 2

~8-5m, where m is number of O double bonded to E group

Question 3

Why strength of acid is independent of number of OH groups present?

Answer 3

Because OH groups do not delocalise charge on anion/

Question 4

For each E=O moiety how strength of acid and pK_a changes?

Answer 4

Strength of acid increases by 10⁵ and pK_a decreases by 5

Question 5

What are 4 general principles of phosphorus oxyacids?

Answer 5

1. All contain 4 coordiante P; at least one P=O
2. At least one P-OH (ionisible)
3. May contain P-H (non-ionisable)
4. Can polymerise - chains or rings vis P-O-P or P-P

Question 6

What acid ends in -ous?

Answer 6

Acids that have oxydation state of +IV like SO₂, SeO₂, TeO₂

Question 7

What acids ends in -ic?

Answer 7

Acids that has oxydation state of +VI, like SO₃, SeO₃, TeO₃

Question 8

How the form of HOX oxyacids are called?

Answer 8

Hypohalous, like NaOCl

Question 9

How the form of HOXO oxyacids are called?

Answer 9

Halous, (chlorides or bromites)

Question 10

How the form of HOXO₂ oxyacids are called?

Answer 10

Hallic (chlorates, bromates, iodates)

Question 11

How the form of HOXO₃ oxyacids are called?

Answer 11

Perhalic (perchlorates, perbromates, periodates)

Question 12

What are chalcogens?

Answer 12

Group 16 elements

Question 13

How ozone is formed?

Answer 13

O₃ formed at high electrical potential at a surface in an ozonizer, and low concentrations under UV irradiation.

Question 14

What is structure of ozone?

Answer 14

Question 15

With what elements oxygen react?

Answer 15

With every element exept He, Ne, Ar.

Question 16

What are allotropes?

Answer 16

Chemical elements that exist in two or more different forms. Example: sulfur (octasulfur and hexasulfur)

Question 17

Why sulfur exist is different forms?

Answer 17

Because there is a preference to form single bonds to other S atoms. Also, S-S-S bonds have hugely varying distances and angles. Also, cycles are thermodynamically favoured.

Question 18

Why H₂Sis more volatile than H₂O?

Answer 18

Because H₂S has weaker hydrogen bonding.

Question 19

Why SF₆ is more inert compared to SF₄ and SeF₆?

Answer 19

Because SF₆ jas high S-F bond strength, cordinatively saturated and sterically hindered, also a lack of polarity.

Se-F bond is weaker as Se is larger, more susceptible to attack. Low reactivity mainly due to kinetic factors.

Question 20

What is catenation?

Answer 20

A preference to form a series of single bonds to the same atom.

Question 21

Give properties of Hydrogen sulfide?

Answer 21

Hydrogen sulfide is a common of sulfur. It has a similar molecular structure to but is as as hydrogen cyanide. The boiling point of H₂S is much lower than that of H₂O.

Question 22

What are chalcogen hydrides?

Answer 22

Binary compounds of hydrogen with chalcogen atoms (group 16)

Question 23

What are halogens?

Answer 23

Group 17 elements

Question 24

What is general trend of halogens?

Answer 24

Going down the group ionisation energy decreases, electron affinity decreases, electronegativity decreases, radii increases, oxidation states increases.

Question 25

What are chemical properties of halogens?

Answer 25

Very reactive- direct combination with most elements. Both ionic and covalent compounds are formed.