1
You visited us
1
times! Enjoying our articles?
Unlock Full Access!
Byju's Answer
Standard XII
Chemistry
Internal Energy
The standard ...
Question
The standard enthalpies of formation of
A
l
2
O
3
and
C
a
O
are
−
1675
k
J
m
o
l
−
1
and
−
635
k
J
m
o
l
−
1
respectively. For the reaction
3
C
a
O
+
2
A
l
→
3
C
a
+
A
l
2
O
3
the standard reaction enthalpy,
Δ
r
H
0
=
________kJ. (Round off to the Nearest Integer)
Open in App
Solution
We know,
Δ
r
H
0
=
Δ
r
H
0
f
(
Products
)
−
Δ
r
H
0
f
(
Reactants
)
=
Δ
r
H
0
f
(
A
l
2
O
3
)
−
3
×
Δ
r
H
0
f
(
C
a
O
)
Δ
r
H
0
=
−
1675
−
3
(
−
635
)
Δ
r
H
0
=
−
1675
+
1905
Δ
r
H
0
=
230
k
J
Suggest Corrections
0
Similar questions
Q.
The standard enthalpies of formation of
A
l
2
O
3
and
C
a
O
are
−
1675
k
J
m
o
l
−
1
and
−
635
k
J
m
o
l
−
1
respectively.
For the reaction,
3
C
a
O
+
2
A
l
→
3
C
a
+
A
l
2
O
3
the standard reaction enthalpy,
Δ
r
H
0
=______kJ (Rounded off to the Nearest Integer).
Q.
The standard enthalpy of formation of
H
2
O
(
l
)
and
F
e
2
O
3
(
s
)
are respectively
−
286
k
J
m
o
l
−
1
and
−
824
k
J
m
o
l
−
1
. What is the standard enthalpy change for the following reaction?
F
e
2
O
3
(
s
)
+
3
H
2
(
g
)
⟶
3
H
2
O
(
l
)
+
2
F
e
(
s
)
Q.
F
e
2
O
3
+
2
A
l
→
A
l
2
O
3
+
2
F
e
The above reaction is an example of a :
Q.
The average
S
−
F
bond energy in
k
J
m
o
l
−
1
of
S
F
6
is _____.(Rounded off to the nearest integer
[Given : The values of standard enthalpy of formation of
S
F
6
(
g
)
,
S
(
g
)
a
n
d
F
(
g
)
are - 1100, 275 and 80 kJ
m
o
l
−
1
respectively]
Q.
If
1
2
moles of oxygen combine with aluminum to form
A
l
2
O
3
, then the weight of aluminum metal used in the reaction is:
2
A
l
+
3
2
O
2
⟶
A
l
2
O
3
View More
Join BYJU'S Learning Program
Grade/Exam
1st Grade
2nd Grade
3rd Grade
4th Grade
5th Grade
6th grade
7th grade
8th Grade
9th Grade
10th Grade
11th Grade
12th Grade
Submit
Related Videos
First Law of Thermodynamics
CHEMISTRY
Watch in App
Explore more
Internal Energy
Standard XII Chemistry
Join BYJU'S Learning Program
Grade/Exam
1st Grade
2nd Grade
3rd Grade
4th Grade
5th Grade
6th grade
7th grade
8th Grade
9th Grade
10th Grade
11th Grade
12th Grade
Submit
AI Tutor
Textbooks
Question Papers
Install app