Please answer the question shown in the image above .
MANASWI SHUKLA , 6 Years ago
Grade 12th pass
Physical Chemistry> Please answer the question shown in the i...
1 AnswersChhavi Jain
Last Activity: 6 Years ago
Dear student ,
NH3 (aq) + H2O (l) ---------> NH4+ (aq) + OH- (aq)
t=0 c mol L-1 – –
t=eqbm c( 1 – α ) – cα cα
( c ---> is the concentration in mol/ L; α----> degree of dissociation )
Now , Kb = [ NH4+] [ OH-] / [ NH3]
= (cα * cα ) / c( 1 – α )
= cα2 / ( 1 – α )
Assuming the value of ‘ α ‘ is very less than 1 we can take (1 – α ) ≈ 1
So, Kb = c α2
1.8 *10-5 = 1.75 α2
α = 0.32 * 10-2 (our assumption is correct )
now , [ OH- ] = cα = 1.75 * 0.32 *10-2 = 0.56 * 10-2
So, pOH = -log [OH-] = – log ( 0.56 * 10-2 ) = 2 – log( 0.56)
pH + pOH = 14
Therefore , pH = 14 – {2 – log(0.56)} = 12+ (-0.251) = 11.749
Chemistry Consultant
Askiitians
Provide a better Answer & Earn Cool Goodies
Enter text here...
LIVE ONLINE CLASSES
Prepraring for the competition made easy just by live online class.
Full Live Access
Study Material
Live Doubts Solving
Daily Class Assignments
Ask a Doubt
Get your questions answered by the expert for free
Enter text here...
Other Related Questions on Physical Chemistry
Which of the following aqueous solutions remains neutral afterelectrolysis
Physical Chemistry
0 Answer Available
Last Activity: 2 Year ago(s)
In the reaction A + 2B ⇌ 2C, if 2 moles of A, 3 moles of B and 2 moles of C are placed in a 2 L flask andthe equilibrium concentration of C is 0.5 mol/L. The equilibrium constant (KC) for the reaction is.....and please tell how you know that the reaction is going forward .. imean how to calculate the reaction quotient ???
Physical Chemistry
1 Answer Available
Last Activity: 2 Year ago(s)
True or false when an electron in ground state of hydrogen atom is excited with an energy that is greayer than e2-e1 but less than e3-e1 the electron will get excited n=2
Physical Chemistry
1 Answer Available
Last Activity: 2 Year ago(s)
18 19 gram mixture of na2co3 and nahco3 on heating gives 2.2 gram CO2 gas find the percent nahco3 (by mass) in mixture
Physical Chemistry
1 Answer Available
Last Activity: 2 Year ago(s)