- Organic Chemistry
- Aldehydes and Ketones
- Alkyl Halides, Alcohols and ethers
- Amines and other nitrogen compounds
- Aromatic Chemistry
- Carbohydrates, Amino acids, protein, Vitamin and Fat
- Carboxylic acids and its derivatives
- Chemistry in daily life
- General Mechanism in organic compounds
- Hydrocarbons
- Nomenclature and isomerism
102 - Physical Chemistry Questions Answers
sub atomic particle
Very soon, we will submit
Q what vol. of O2 OBTAINED AT ANODE AT STP IF Aq SOLn OF CuSO4 IS ELECTROLYSED BY PASSG 100A CURRENT FOR 60 MIN? ANS 20.89L
Total charge flown in the circuit = 100*60*60 = 360000 coulomb
so no of faradays of electricity = 360000/96500 = 3600/965 = 3.73 F
so amount of O2 = 3.73*5.6 = 20.89 litre
Here 5.6 litre is eq. volume corresponding to 8 gm. of O2
SIR , I WANT TO KNOW THAT IN THE EQUILM QUES WHY YOU TAKE MOL FRACT FOR CH3COCH3=1-1/6-1/6.WHY YOU SUB FROM 1.
If we multiply mole fraction to pressure, we get the pressure exerted by the component so it is a good way to get answer. and 1 represents net sum of mole fractions of all the components. here first and second 1/6 stands for mole fraction of ethane and carbon monooxide.
Q In NAcL type str of A+ &B- ,2A ATOMS ARE REMOVED FROM EDGES &2B ATOMS ARE REMOVED FROM CORNER. FORMULA=? ANS =A14B15 . HOW?
In NaCl like structure B covers all the corners and face centre and A covers all the edge centres and body centre
Net contribution of B = 8*1/8 + 6*1/2 = 4
Net contribution of A = 12*1/4 + 1*1 = 4
now 2 A ATOMS ARE REMOVED FROM EDGES so remaining contribution = 10*1/4 + 1*1 = 7/2
and 2 B ATOMS ARE REMOVED FROM CORNE so remainnig contribution = 6*1/8 + 6*1/2 = 15/4
so formula will be A7/2B15/4 or A14B15
Q CH3COCH3 (g) eqm CH3CH3 +CO
initial pressure of CH3COCH is 300 mm when eqm is setup mole fraction of CO(g) = 1/6 hence total pressure will be =?
ANS 360mm of hg .SOL =?
At equilibrium mole fraction of CO = 1/6, that of CH3CH3 = 1/6
so mole fraction of CH3COCH3 = 1- 1/6 - 1/6 = 2/3
let the total pressure at equilibrium = p
so pressure of CH3CH3 and CO will be p/6 and p/6
and that of CH3COCH3 = 2p/3
now consider the following dissociation data
CH3COCH3 ----> CH3CH3 + CO
300 mm 0 0 at starting
300-x mm x x at equilibrium
here x = p/6 (1) and 300-x = 2p/3 (2) add these equations and get the value of p
Sir can you please post a topic on ionic equilibrium ( especially for numerical solving).
YES
very soon
The change in standard gibbs free energy of given cell at NTP
Zn I Zn(2+) II OH- I Ag2O I Ag Eo =1.104V
Zn -----> Zn++ + 2e-
Ag2O + H2O + 2e- ------> 2Ag + 2OH-
so Gibbs free energy change = nFE = 2*96500*1.104
A CURRENT OF 0.25 A IS PASSED THROUGH 400ML OF A2.0 M SOLN OF NaCl FOR 35 MINUTES.WHAT WILL BE THE PH OF THE SOLN AFTER THE CURRENT IS SWITCHED OFF?
q = it = 0.25*35*60 = 525 coul.
so no. of eq.( of H2) formed = 525/96500 = 21/3860, same will be the no. of moles
total initial no. of moles of NaCl = 2*0.4 = 0.8 moles
remaining no. of moles of H+ = 0.8 - (21/3860)
so pH = -log[H+]
N2 gas is formed by electrolysis of magnesium nitride .The volume of one equivalent of N2 gas evolved at NTP is
Mg3N2 −−−−> 3 Mg + N2
so n factor of N = 3 , for N2 it will be 6, so one equivalent of N2 = 22.4/6 = 11.2/3
what is difference between dissociatio and ionisation?
Dissociation is the reaction in which two or more than two product molecules are formed.
ex. PCl5 ---> PCl3 + Cl2
whereas ionisation is the reaction in which ions are formed
ex. MgCl2 ----> Mg++ + 2 Cl-