- 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
10 ml of M/200 H2SO4 is mixed with 40 ml of M/200 H2SO4. The ph of the resulting solution is
M of H2SO4 = 1/200
so [H+] = 2*1/200 = 1/100 = 10-2
now calculate pH
The pH of solution at 25°C which has twice as many hydroxide ion as in pure water at 25°C , will be
no of hydroxide ion in pure water = 10-7
so according to the given condition no. of hydroxide ions in solution = 2*10-7
so pOH = -log2*10-7
so pH = 14 - pOH
The ph of 0.1 M HCN is 5.2. What is the Ka?
HCN -------------------> H+ + CN-
0.1 0 0
0.1-x x x
pH = 5.2
so -log[H+] = 5.2
solve for [H+], it will give x
then calculate Ka
ΔHf C2H4 = 12.5 kcal
Heat of atomization of C = 171 kcal
Heat of atomization of H = 52.1 kcal
Bond energy C−H = 99.3 kcal .
What is C=C bond energy?
2 heat of atomization of C + 4 heat of atomization of H - 4 bond energy of C-H - 1 bond energy of C=C = heat of formation of C2H4
2*171 + 4*52.1 - 4*99.3 - x = 12.5
solve
How Is the value of n calculated for nerst equation??
n is the no. of electrons in anode or cathode reaction.
If no. of electrons are different then make these no. common
for ex. if reactions are
Al ---------------> Al+++ + 3e-
and Cu++ + 2e- ------------> Cu
then multiply (1) to 2 and (2) to 3
after that electrons will be 6 in both reactions so n = 6
Integral enthalpy of soln of KCl , when 1 mole of it is dissolved in 20 mole water is +15.90kJ . When 1 mole of it is dissolved in 200mole water dH =15.58kJ. Calculate enthalpy of hydratn or dilutn ??
ans is 2.68kJ
Integral enthalpy
please check this word if wrong submit the correct question again
show that (du/dv)s=T-sdp
question is incorrect
because (du/dv)s represents pressure and T is temperature
q. = Mass of solution of 1 molal glucose solution to get 0.2 molal glucose is.
a.200
b.300
c.236
d.108
I think question is incomplete, correct it first
acetic acid in a solvent undergoes 20% dissociation and 70% association, find vant hoff factor.
CH3COOH = CH3COO- + H+
1 0 0
0.8 0.2 0.2
CH3COO- + H+ = CH3COOH
0.2 0.2 0.8
0.06 0.06 0.8+0.14
0.06 0.06 0.94 sum = 1.06
so i = 1.06/1 = 1.06
calculate the molecular weight of cellulose acetate if its 0.2%wt/vol solution in acetone(sp. gravity 0.8) shows osmotic rise of 23.1mm against pure acetone at 27C.
By formula πV = nRT
π = hdg, n=w/M
given
0.2%wt/vol solution in acetone means w= 0.2 gm, V = 100 ml= 100/1000 litre = 0.1*10-3 m3 , h = 23.1/1000 m, d = 800 kg/m3 ,
now solve