T1- p Block LP5 Flashcards
What are oxyacids?
Acids in the form of OmE(OH)n where E is p block compound
Using Pauling rules, what is pKa of oxyacids in water?
~8-5m, where m is number of O double bonded to E group
Why strength of acid is independent of number of OH groups present?
Because OH groups do not delocalise charge on anion/
For each E=O moiety how strength of acid and pKa changes?
Strength of acid increases by 105 and pKa decreases by 5
What are 4 general principles of phosphorus oxyacids?
- All contain 4 coordiante P; at least one P=O
- At least one P-OH (ionisible)
- May contain P-H (non-ionisable)
- Can polymerise - chains or rings vis P-O-P or P-P
What acid ends in -ous?
Acids that have oxydation state of +IV like SO2, SeO2, TeO2
What acids ends in -ic?
Acids that has oxydation state of +VI, like SO3, SeO3, TeO3
How the form of HOX oxyacids are called?
Hypohalous, like NaOCl
How the form of HOXO oxyacids are called?
Halous, (chlorides or bromites)
How the form of HOXO2 oxyacids are called?
Hallic (chlorates, bromates, iodates)
How the form of HOXO3 oxyacids are called?
Perhalic (perchlorates, perbromates, periodates)
What are chalcogens?
Group 16 elements
How ozone is formed?
O3 formed at high electrical potential at a surface in an ozonizer, and low concentrations under UV irradiation.
What is structure of ozone?
With what elements oxygen react?
With every element exept He, Ne, Ar.
What are allotropes?
Chemical elements that exist in two or more different forms. Example: sulfur (octasulfur and hexasulfur)
Why sulfur exist is different forms?
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.
Why H2Sis more volatile than H2O?
Because H2S has weaker hydrogen bonding.
Why SF6 is more inert compared to SF4 and SeF6?
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.
What is catenation?
A preference to form a series of single bonds to the same atom.
Give properties of Hydrogen sulfide?
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.
What are chalcogen hydrides?
Binary compounds of hydrogen with chalcogen atoms (group 16)
What are halogens?
Group 17 elements
What is general trend of halogens?
Going down the group ionisation energy decreases, electron affinity decreases, electronegativity decreases, radii increases, oxidation states increases.
