Welcome to Chem Zipper.com......: 17th Group HALOGENS FAMILY

Search This Blog

Showing posts with label 17th Group HALOGENS FAMILY. Show all posts
Showing posts with label 17th Group HALOGENS FAMILY. Show all posts

Sunday, January 17, 2021

What is the structure of (O2F2) oxygen fluoride

The compound id produced as result of glow dischage through amixture of O2 and F2 at -180 to -190 degree (c). As should be expected. O2F2 is an extremely reactive fluorinating agent. Under the conditions that produce OF2, small and O4F2 are produced, but these unstable compounds decomposed at liquid nitrogen temperatures.

Why Bond length of O-O is greater in H2O2 than O2F2?

Electronegativity of F is much more than hydrogen and also hybridization of oxygen atoms in of H2O2 and O2F2 both have (sp3) same and hence we can apply bent’s rule.

According bent’s rule more eletronegative atoms reduce % s-character (or increases % p-character vice versa) of those hybride orbital in which they attach. So in case of O2F2 % s-character of those hybride orbital decrease which have  flourine while % p-character increases in same way % s-character of  remaing hybride orbital inceases and p-character decreases hence its bond length also (bond length is directly proportional to % p-character) decreases.  hence O-O bond length in O2F2 is shorter thane H2O2.

Related Questions:

What is Bent’s rule of hybridization?

Which of the following compound have longest (S=O)bond length , O=SF2, O=SCl2, O=SBr2.

Oxides of Halogens;

Halogens and oxygen they do not combine directly with oxygen due to high electron affinity of both halogens and oxygen but their oxides with oxygen can be prepared indirectly.

The compounds of oxygen with fluorine are called as fluorides (not a oxide) because fluorine is more electronegative than oxygen. Most of these compounds are endothermic and unstable and are likely to explode resulting in the formation of more stable products.

The compounds of chlorine ,bromine and Iodine with oxygen are called oxide because electronegtivity of oxygen is greater than these. And the common oxides of halogens are X2O, X2O3, X2O5, and X3O7 (common oxidation state of 17th group) and uncommon oxides are ClO2 (+4) and ClO3/Cl2O6 etc.

 

Flourine

O.S.

Chlorine

Bromine

Iodine

OF2 &O2F2

(+1) /X2O

Cl2O

Br2O

 

 

(+3)/X2O3

 

 

 

 

(+4)

ClO2/Cl2O4

BrO2

I2O4

 

(+5)/X2O5

 

 

I2O5

 

(+6)

ClO3/Cl2O6

BrO3

 

 

(+7)/X2O7

Cl2O7

 

 

 

All the oxides are powerful oxidizing agents and decompose explosively when they are given mechanical shock or heat.

Structure of  chlorine oxides:

Structure of dichlorine heptaoxide:                   

Avarage oxidation state of Chlorine in Cl2O7 is one of the common oxidation state of the chlorine so there is (Cl-O-Cl) Oxy-linkage will be present. And one of oxygen atom is shared by both of chlorine atoms and rest of the oxygen atoms equally distributed.

The whole molecule dichlorine heptaoxide (Cl2O7) is non planer and polar and oxygen atom of (Cl-O-Cl) oxy-linkage does not involve in delocalization due to maximum repulsion hence two Cl-O bond have equal length and bond order may be/equal to one while other six Cl=O bond have eqaual bond length

In dichlorine heptaoxide (Cl2O7) , two ClO4 group connected with an oxygen atom which is sp3 hybridised (non planer) and bond angle may be expected 109⦁28’ but actually due to the presence of two lone pair on oxygen atom the Cl-O-Cl bond angle deviated from ideal and it may be greater (119⦁) than ideal bond angle.

Question (1): Number of sigma  and pi bonds present in Cl2O7 is/ are ....?

Number of sigma and pi bond present in Cl2O7 are (8) and (6) repectively.

Question(2):What is the anhydride of  HClO4 ?

Cl2​O7​ is the anhydride of  HClO4

Question (3):Number of equivalent Cl-O bond in Cl2O7 is/are….

Number of equivalent Cl-O bond in Cl2O7 are (2) two.

 

Question(4):Number of equivalent Cl=O bond in Cl2O7 is/are….

Number of equivalent Cl=O bond in Cl2O7 are (6) six.

Related Questions:




Trisilyl amine, N(SiH3)3 is planar whereas trimethyl amines N(CH3)3 is pyramidal. Explain why?.















What is the structure and structural characteristic of dichlorine heptaoxide (Cl2O7)?

Avarage oxidation state of Chlorine in Cl2O7 is one of the common oxidation state of the chlorine so there is (Cl-O-Cl) Oxy-linkage will be present. And one of oxygen atom is shared by both of chlorine atoms and rest of the oxygen atoms equally distributed.

The whole molecule dichlorine heptaoxide (Cl2O7) is non planer and polar and oxygen aotm of (Cl-O-Cl) oxy-linkage does not involve in delocalization due to maximum repulsion hence two Cl-O bond have equal length and bond order may be/equal to one while other six Cl=O bond have eqaual bond length.

In dichlorine heptaoxide (Cl2O7) , two ClO4 group connected with an oxygen atom which is sp3 hybridised (non planer) and bond angle may be expected 109⦁28’ but actually due to the presence of two lone pair on oxygen atom the Cl-O-Cl bond angle deviated from ideal and it may be greater (119⦁) than ideal bond angle.

Question (1): Number of sigma  and pi bonds present in Cl2O7 is/ are ....?

Answer: Number of sigma and pi bond present in Cl2O7 are (8) and (6) repectively.

Question(2):What is the anhydride of  HClO4 ?

Answer: Cl2​O7​ is the anhydride of  HClO4

Question (3):Number of equivalent Cl-O bond in Cl2O7 is/are….

Answer Number of equivalent Cl-O bond in Cl2O7 are (2) two.

 

Question(4):Number of equivalent Cl=O bond in Cl2O7 is/are….

Answer:Number of equivalent Cl=O bond in Cl2O7 are (6) six.


Related Questions:

(1) Why halogens are insoluble in water ?
(2) Is F2 bond is stronger than Br2 ?
(3) Which is best known pseudohalide ?
(4) Iodine forms I3- but F2 does not form F3- ions. Why?
(5) Number of lone pair present at central atom of I3- ion and also give hybridisation and shape of ion?
(6) How many maximum atoms of IF7 are present in the same plane ?
(7) What are the Pseudohalogens or halogenoids?
(8) What are Pseudohalides ? and What is similarity with halides?
(9) Although electron affinity of chlorine is higher than fluorine, yet fluorine act as better oxidizing agent than chlorine? Explain.
(10) Although electron affinity of chlorine is higher than fluorine, yet fluorine act as better oxidizing agent than chlorine? Explain.
(11) Why chlorine trifluoride (ClF3) exists but fluorine trichloride (FCl3) does not?
(12) Why Chlorine (Cl2) bleaches a substance permanently but sulphuredioxide (SO2) does it temporarily?
(13) What is the correct order of electronegativity of Cl atoms in HClO, HClO2, HClO3 and HClO4 ?
(14) How does the thermal stability of oxy acids of chlorine increase with an increase in the oxidation state of chlorine atom ?
(15) Which of the following is a strongest acid among oxy acids of chlorine and why? "HClO, HClO2, HClO3, HClO4"
(16) Which will have very fast tendency to dimerized ClO2 or NO and why?
(17) Which of the following is a strongest acid among oxy acids of chlorine and why? "HClO, HClO2, HClO3, HClO4"

Friday, January 15, 2021

Oxy acids of Chlorine:

Chlorine, bromine and Iodine form oxy acids easly due to less electronegative than oxygen but oxy acids of fluorine are unsatble due to high electronegativity only hypofluorous (HOF) acid is stable.

O.S of halogens

Name of acids

Name of  salts

fluorine

Chlorine

Bromine

Iodine

(+1)

Hypohalous

Hypohalite

HOF

HOCl

HOBr

HOI

(+2)

Halous

Halite

----

HClO2

----

----

(+3)

Halic

Halate

----

HClO3

HBrO3

HIO3

(+4)

Perhalic

Perhalate

----

HClO4

HBrO4

HIO4


Important Note:
All the hypohalous acids (HXO) are unstable and readly form HXO3. Among the relative order of stability is: HClO > HBrO > HIO

Relative acidic strength of oxy acid Halogens:

(1) According to Bronsted Lowery concept, a strong acid has weak conjugate base and vice versa. 

The given oxy acids of chlorine HCIO, HCIO2, HClO3 and HClO4 and their conjugate bases are CIO-, CIO2-, ClO3-, ClO4- respectively. These anions are stabilised to greater extent, due to the presence of π-bond and lone pair, if number of π-bond increase extent of stabilisation increase. In case of ClO- there is no π-bond hence if form less stable conjugate base hence act as weak acid while in case of ClO4- it has three pπ-dπ bond which stablised greater extent and form more stable conjugate base hence it conjugate acid (HClO4) is strongest acid. Oxy acids of chlorine and their number of pπ-dπ bonds given as:

HOCI (0=Pπ-dπ bond)

HOCIO (1=Pπ-dπ bond)

HOClO2 (2=Pπ-dπ bond)

HOCIO3 (3=Pπ-dπ bond)

Thus overall order of acidic strength of oxy acids of chlorine is as:

Acidic srength of acid as :  (HClO) < (HClO2)<(HClO3)<(HClO4

(2) In general the relative strength of oxy acid can pridicted on the basis of electronegativity and oxidation state of central non metal atom.

(1) For given oxy acid on increasing of electronegativity acidic strength increses for example perchloric (HClO4) is stronger acid than perbromic acid(HBrO4), which should be a stronger acid than periodic acid (HIO4) because the electronegativity of the central atom increses as (Cl>B>I).

Acidic srength of acid as :  (HIO4)< (HBrO4)<(HClO4)

(2) For given non metal oxy acid the strength of oxy acid increases as the oxidation state of central atom increases for example; "HClO (+1),HClO2(+3), HClO(+5), HClO4(+7) 

Acidic srength of acid as :  (HClO)< (HClO2)<(HClO3)<(HClO4)

Relative  oxidizing character of oxy acid of Halogens:

Hypochlorous (HClO) act as the best oxidizing agent because it give nascent oxygen easily.

                                 HClOàHCl + O (nascent oxygen)

Order of oxiding character:  (HClO4)<(HClO3)<(HClO2)<(HClO)

Relative  thermal stability of oxy acid of Halogens:

As the number of pπ-dπ bond incrases bond strength incrases and thus order of thermal stability also increases.

Thermal stability order: (HClO)< (HClO2)<(HClO3)<(HClO4)

Relative (Cl-O) bond order and bond length

HOCI (0=Pπ-dπ bond)     BO=1

HOCIO (1=Pπ-dπ bond)  BO=1.5

HOClO2 (2=Pπ-dπ bond) BO=1.66

HOCIO3 (3=Pπ-dπ bond) BO=1.75

Hence (Cl-O) single bond length order as: (HClO)>(HClO2)>(HClO3)>(HClO4)

Question: which set of properties follow given order:

(HClO)< (HClO2)<(HClO3)<(HClO4)

(i) Acidic nature (ii) Oxidizing nature(iii) Thermal stability (iv) Cl-O single bond

(A) Only (i) (B) Only (i) & (iii) (C) Only (i), (iii) & (iii) (D) All of these

Answer Key: (B)

Related Questions:

Why halogens are insoluble in water ?
Is F2 bond is stronger than Br2 ?
Which is best known pseudohalide ?
Iodine forms I3- but F2 does not form F3- ions. Why?
Number of lone pair present at central atom of I3- ion and also give hybridisation and shape of ion?
How many maximum atoms of IF7 are present in the same plane ?
What are the Pseudohalogens or halogenoids?
What are Pseudohalides ? and What is similarity with halides?
Although electron affinity of chlorine is higher than fluorine, yet fluorine act as better oxidizing agent than chlorine? Explain.
Although electron affinity of chlorine is higher than fluorine, yet fluorine act as better oxidizing agent than chlorine? Explain.
Why chlorine trifluoride (ClF3) exists but fluorine trichloride (FCl3) does not?
Why Chlorine (Cl2) bleaches a substance permanently but sulphuredioxide (SO2) does it temporarily?
What is the correct order of electronegativity of Cl atoms in HClO, HClO2, HClO3 and HClO4 ?
How does the thermal stability of oxy acids of chlorine increase with an increase in the oxidation state of chlorine atom ?
Which of the following is a strongest acid among oxy acids of chlorine and why? "HClO, HClO2, HClO3, HClO4"
Which will have very fast tendency to dimerized ClO2 or NO and why?
Which of the following is a strongest acid among oxy acids of chlorine and why? "HClO, HClO2, HClO3, HClO4"