Thursday 31 December 2015
Q.No.42: Can Chlorine make H-Bond??? - Malik Xufyan
Organic Reaction Mechanisms: A Step by Step Approach, Second Edition By Michael EdenborougH Page # 98
Refrence : Organic Chemistry BY R.L.Madan page # 81
Refrence :First Year Chemistry PT book Pakistan page # 84-85
AS Chemistry for AQA By John Atkinson, Carol Hibbert page # 34
Note: there is something wrong in above refrence , oxygen and chlorine has not same electronegativity , oxygen has high electronegativity than chlorine.
here should nitrogen not oxygen
thanx
Malik Xufyan
here should nitrogen not oxygen
thanx
Malik Xufyan
Wednesday 30 December 2015
Tuesday 29 December 2015
Sunday 27 December 2015
Q :1 Why Ozone is unstable than oxygen ?
Reasoning Question series
Q :1
Why Ozone is unstable than oxygen ?
Ans :
ozone has three oxygen atoms while oxygen have 2 oxygen atoms. ozone forms trigonal structure in which one oxygen make weak bond with other oxygen atom.
thats why ozone is more reactive than oxygen
Regards
Malik Xufyan
Q :1
Why Ozone is unstable than oxygen ?
Ans :
ozone has three oxygen atoms while oxygen have 2 oxygen atoms. ozone forms trigonal structure in which one oxygen make weak bond with other oxygen atom.
thats why ozone is more reactive than oxygen
Regards
Malik Xufyan
Q:2 why Flourine has dissociation energy than Chlorine and bromine?
Reasoning Question series
Q:2 why Flourine has dissociation energy than Chlorine and bromine?
Ans :
Cl2 > Br2 > F2 > I2
1. bond dissociation energy decreases down the group from chlorine to iodine
an exceptional case of Flourine which have less than the chlorine and bromine
there are two factors for this
2. Bond length .... bond length increases down the group from chlorine to iodine . thats why bond dissociation is inversaly proportional to bond length 3. Repulsion forces ........... repulsion factor is more strong factor than bond length
this factor is present in Flourine due to small size
thats why flourine has lower value than chlorine and bromine
Regards
Malik Xufyan
Q:2 why Flourine has dissociation energy than Chlorine and bromine?
Ans :
Cl2 > Br2 > F2 > I2
1. bond dissociation energy decreases down the group from chlorine to iodine
an exceptional case of Flourine which have less than the chlorine and bromine
there are two factors for this
2. Bond length .... bond length increases down the group from chlorine to iodine . thats why bond dissociation is inversaly proportional to bond length 3. Repulsion forces ........... repulsion factor is more strong factor than bond length
this factor is present in Flourine due to small size
thats why flourine has lower value than chlorine and bromine
Regards
Malik Xufyan
Q:4 why resistance of semi conductor decreases with the increase in temperature ?
Reasoning question series
Q:4 why resistance of semi conductor decreases with the increase in temperature ?
Ans :
There are two bands in semiconductors
1. valance band
2. conduction band
jumping electrons from valance band to conduction band needs higher amount of energy
thats why with increasing temperature increase the conductivity of semiconductors.
Regards
Malik Xufyan
Q:4 why resistance of semi conductor decreases with the increase in temperature ?
Ans :
There are two bands in semiconductors
1. valance band
2. conduction band
jumping electrons from valance band to conduction band needs higher amount of energy
thats why with increasing temperature increase the conductivity of semiconductors.
Regards
Malik Xufyan
Wednesday 23 December 2015
Tuesday 22 December 2015
Friday 18 December 2015
Thursday 17 December 2015
Monday 14 December 2015
0.1 N H2S04 solution Formation
Liquid solutions have many problems . if in this have any mistake plz tell me Two Things are important to making Liquid solutions 1. %age purity of Chemical 2. Specific Gravity or density of Chemical
These informations are printed on Bottles of Chemical in LabThen for Normal Solution to determine the equivalant mass of Chemical %% Now Start %% :
The specific gravity for H2SO4 =1.84%age purity of H2SO4 = 97 % Gram-formula weight of H2SO4 = 98/2 = 49 gGrams of compound needed = (N desired)(equivalent mass)(volume in liters desired). Substituting the above numbers into the equation, we get:
grams of compound needed = (0.1 N)(49)(1 liters) = 4.9 grams.Volume of concentrated acid needed = (grams of acid needed)/(percent concentration x specific gravity)volume of concentrated acid needed = (4.9 grams)/(0.97 x 1.84) = 8.74 mL
Note:If you took 8.74 mL of concentrated sulfuric acid and diluted it to 1 L , you would have a 0.1 N H2SO4 solution.
Sunday 13 December 2015
37 % HCl Solution formation
Liquid Solution preparation procedure smile emoticon
Mass of HCl = 37% x 100 g = 37 g
Moles of HCl = mass/ Mr = 37 / ( 1.008+35.45) = 1.015 mol
Mass of water = mass of solution – mass HCl
Mass of water = 100-37 = 63 g
Remember the density of water is 1 g/mL thus 63 g of water equal to 63 mL so we can get the molarity of HCl solution
Molarity of HCl = mol/volume = 1.015 mol/0.063 L = 16.11 M
You can use this formula for the dilution calculation ( this calculation is made if you want to prepare 0.1 M HCl 1000 mL)
M1V1=M2V2
16.11.V1 = 0.1 x 1000
V1 = 6.21 mL
So just pipette 6.21 mL of HCl 37% and than dilute it by adding water until the volume reach 1000 mL
Mass of HCl = 37% x 100 g = 37 g
Moles of HCl = mass/ Mr = 37 / ( 1.008+35.45) = 1.015 mol
Mass of water = mass of solution – mass HCl
Mass of water = 100-37 = 63 g
Remember the density of water is 1 g/mL thus 63 g of water equal to 63 mL so we can get the molarity of HCl solution
Molarity of HCl = mol/volume = 1.015 mol/0.063 L = 16.11 M
You can use this formula for the dilution calculation ( this calculation is made if you want to prepare 0.1 M HCl 1000 mL)
M1V1=M2V2
16.11.V1 = 0.1 x 1000
V1 = 6.21 mL
So just pipette 6.21 mL of HCl 37% and than dilute it by adding water until the volume reach 1000 mL
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