NCERT Solutions
Board Paper Solutions
Ask & Answer
School Talk
Login
GET APP
Login
Create Account
Popular
Latest
Expert Answers
ALL
Chharishma.r.nayaka
Subject: Chemistry
, asked on 5/2/18
Plz ans it as soon as possible...its urgent...its 4 methnol..
Q32A). Calculate the standard enthalpy of formation of CH
3
OH
(e)
.If standard enthalpy of combustion of carbon, hydrogen and benzene are 726 KJ mol
–1
, –393 KJ mol
–1
and –286 KJ mol
–1
respectively.
Answer
1
Chharishma.r.nayaka
Subject: Chemistry
, asked on 5/2/18
Solve this :
A. Calculate the standard enthalpy of formation of benzene. Give that the enthalpies of combustion of carbon, hydrogen and Benzene are -393.5 KJ/mol, -285.83 KJ/mol, -3267 KJ/mol respectively.
B. State the law of thermodynamics.
Answer
2
Chharishma.r.nayaka
Subject: Chemistry
, asked on 3/2/18
36. A) Describe the estimation of sulphur by carius method.
Answer
2
Chharishma.r.nayaka
Subject: Chemistry
, asked on 3/2/18
Plz ans dis ques...as so as possible...plz
Q. B). What is electromeric effect? Which type of electromeric effect shown by
H
+
?
Answer
2
Chharishma.r.nayaka
Subject: Chemistry
, asked on 3/2/18
Plz ans dis ques....& give me d ans 4 benzene..nt 4 methane...plz ans...as so as possible...
Q.31. A). Calculate the standard enthalpy of formation of benzene. Give that the enthalpies of combustion of carbon, hydrogen and Benzene are - 393.5 KJ/mol, - 285.83 KJ/mol, - 3267 KJ/mol respectively.
B). State the law of thermodynamics.
Answer
6
Parameswaran Namboothiri
Subject: Chemistry
, asked on 3/2/18
Q.4. When 1 M
H
2
S
O
4
is completely neutralised by sodium hydroxide the heat liberated is 114.64 KJ. What is the enthalpy of neutralisation
1) + 114.64 KJ
2) - 114.64 KJ
3) - 57.32 KJ
4) 75.4 KJ
Answer
1
Chharishma.r.nayaka
Subject: Chemistry
, asked on 2/2/18
31
.
A
C
a
l
c
u
l
a
t
e
t
h
e
s
tan
d
a
r
d
e
n
t
h
a
l
p
y
o
f
f
o
r
m
a
t
i
o
n
o
f
b
e
n
z
e
n
e
.
G
i
v
e
t
h
a
t
t
h
e
e
n
t
h
a
l
p
i
e
s
o
f
c
o
m
b
u
s
t
i
o
n
o
f
c
a
r
b
o
n
,
h
y
d
r
o
g
e
n
a
n
d
B
e
n
z
e
n
e
a
r
e
-
393
.
5
K
J
/
m
o
l
,
-
285
.
83
K
J
/
m
o
l
,
-
3267
K
J
/
m
o
l
r
e
s
p
e
c
t
i
v
e
l
y
.
B
S
t
a
t
e
t
h
e
l
a
w
o
f
t
h
e
r
m
o
d
y
n
a
m
i
c
s
.
Answer
1
Smridhi Verma
Subject: Chemistry
, asked on 28/1/18
Please answer this question
D
i
b
o
r
a
n
e
i
s
a
p
o
t
e
n
t
i
a
l
r
o
c
k
e
t
f
u
e
l
w
h
i
c
h
u
n
d
e
r
g
o
e
s
c
o
m
b
u
s
t
i
o
n
a
c
c
o
r
d
i
n
g
t
o
t
h
e
r
e
a
c
t
i
o
n
:
B
2
H
6
(
g
)
+
3
O
2
(
g
)
→
B
2
O
3
(
s
)
+
3
H
2
O
(
g
)
F
r
o
m
t
h
e
f
o
l
l
o
w
i
n
g
d
a
t
a
,
c
a
l
c
u
l
a
t
e
t
h
e
e
n
t
h
a
l
p
y
c
h
a
n
g
e
f
o
r
t
h
e
c
o
m
b
u
s
t
i
o
n
o
f
d
i
b
o
r
a
n
e
2
B
(
s
)
+
3
2
O
2
(
g
)
→
B
2
O
3
(
s
)
,
∆
H
=
-
1273
k
J
m
o
l
-
1
H
2
(
g
)
+
1
2
O
2
(
g
)
→
H
2
O
(
l
)
,
∆
H
=
-
286
k
J
m
o
l
-
1
H
2
O
(
l
)
→
H
2
O
(
g
)
,
∆
H
=
44
k
J
m
o
l
-
1
2
B
(
s
)
+
3
H
2
(
g
)
→
B
2
H
6
(
g
)
,
∆
H
=
-
36
k
J
m
o
l
-
1
Answer
1
Smridhi Verma
Subject: Chemistry
, asked on 28/1/18
the enthalpy of formation of methane at constant pressure at 300K is -78.84kJ.What will be the enthalpy of formation at constant volume?
Answer
1
Tulsi Mehta
Subject: Chemistry
, asked on 27/1/18
IN THE SOLUTION , WHY IS THE UNDERLINED STEP USED ?
H reactants- H products is for BOND ENTHALPIES RIGHT ?
The heat of combustion of C2H6 is -368.4 kcal. Calculate heat of combustion of C2H4, heat of combustion of H2 is kcal/mol . Delta H for the following reaction is -37.1 kcal.
C2H4(g) + H20(g) --> C2H6(g)
Answer
1
Tulsi Mehta
Subject: Chemistry
, asked on 27/1/18
energy released in neutralisation of H2so4 and koh is 57.1kJ/mol. calculate value of delta H for reaction. H2so4 + koh --> k2so4 + 2h20
Answer
1
Priyanshi
Subject: Chemistry
, asked on 26/1/18
Question 13 give reason why both assertion and reason are correct
13. A : A non-spontaneous process becomes spontaneous when coupled with a suitable spontaneous reaction.
R : The overall free energy of coupled spontaneous reaction is negative.
Answer
2
Priyanshi
Subject: Chemistry
, asked on 26/1/18
ΔH
f
C
2
H
4
= 12.5 kcal
Heat of atomisation of C = 171 kcal Bond energy of H
2
= 104.3 kcal Bond energy C – H = 99.3 kcal what is C = C bond energy?
(1) 140.9 kcal (2) 49 kcal (3) 40 kcal (4) 76 kcal
Answer
2
Khushi Rastogi
Subject: Chemistry
, asked on 24/1/18
Q. Which prop./thermodynamical parameter/prop. remains constant during followings -
(a) liquid evaporates to vapour, (b) free expansion of gas (c) mixing of two gases (d) conversion of rhombic sulphuric to monoclinic sulphur.
Answer
1
Tulsi Mehta
Subject: Chemistry
, asked on 24/1/18
Q. At 60
°
C, dinitrogen tetroxide is fifty percent dissociated. Calculate the standard free energy change at
this temperature and at one atmosphere.
Answer
1
Prev
2
3
4
5
6
Next
What are you looking for?
Q32A). Calculate the standard enthalpy of formation of CH3OH (e) .If standard enthalpy of combustion of carbon, hydrogen and benzene are 726 KJ mol–1, –393 KJ mol–1 and –286 KJ mol–1 respectively.
A. Calculate the standard enthalpy of formation of benzene. Give that the enthalpies of combustion of carbon, hydrogen and Benzene are -393.5 KJ/mol, -285.83 KJ/mol, -3267 KJ/mol respectively.
B. State the law of thermodynamics.
Q. B). What is electromeric effect? Which type of electromeric effect shown by ?
Q.31. A). Calculate the standard enthalpy of formation of benzene. Give that the enthalpies of combustion of carbon, hydrogen and Benzene are - 393.5 KJ/mol, - 285.83 KJ/mol, - 3267 KJ/mol respectively.
B). State the law of thermodynamics.
1) + 114.64 KJ
2) - 114.64 KJ
3) - 57.32 KJ
4) 75.4 KJ
H reactants- H products is for BOND ENTHALPIES RIGHT ?
The heat of combustion of C2H6 is -368.4 kcal. Calculate heat of combustion of C2H4, heat of combustion of H2 is kcal/mol . Delta H for the following reaction is -37.1 kcal.
C2H4(g) + H20(g) --> C2H6(g)
13. A : A non-spontaneous process becomes spontaneous when coupled with a suitable spontaneous reaction.
R : The overall free energy of coupled spontaneous reaction is negative.
Heat of atomisation of C = 171 kcal Bond energy of H2 = 104.3 kcal Bond energy C – H = 99.3 kcal what is C = C bond energy?
(1) 140.9 kcal (2) 49 kcal (3) 40 kcal (4) 76 kcal
(a) liquid evaporates to vapour, (b) free expansion of gas (c) mixing of two gases (d) conversion of rhombic sulphuric to monoclinic sulphur.
this temperature and at one atmosphere.