The standard heats of combustion ( Δ r H ° ) of butane-l ,3-diene, C 4 H 5 ( g ) ; butane, C 4 H 10 ( g ) ; and H 2 ( g ) are − 2540.2 , − 2877.6 , and − 285.8 k J m o l 1 , respectively. Use these data to calculate theheat of hydrogenation of butane-l ,3-diene to butane. C 4 H 6 ( g ) + 2 H 2 ( g ) → C 4 H 10 ( g ) Δ r H ° = ? [Hint: Write equations for the combustion reactions. In each combustion, the products are C O 2 ( g ) and H 2 O ( I ) . ]
The standard heats of combustion ( Δ r H ° ) of butane-l ,3-diene, C 4 H 5 ( g ) ; butane, C 4 H 10 ( g ) ; and H 2 ( g ) are − 2540.2 , − 2877.6 , and − 285.8 k J m o l 1 , respectively. Use these data to calculate theheat of hydrogenation of butane-l ,3-diene to butane. C 4 H 6 ( g ) + 2 H 2 ( g ) → C 4 H 10 ( g ) Δ r H ° = ? [Hint: Write equations for the combustion reactions. In each combustion, the products are C O 2 ( g ) and H 2 O ( I ) . ]
Solution Summary: The author explains that the enthalpy of a reaction is independent of the path taken and it depends upon the initial reactants and final products.
The standard heats of combustion
(
Δ
r
H
°
)
of butane-l ,3-diene,
C
4
H
5
(
g
)
; butane,
C
4
H
10
(
g
)
; and
H
2
(
g
)
are
−
2540.2
,
−
2877.6
,
and
−
285.8
k
J
m
o
l
1
, respectively. Use these data to calculate theheat of hydrogenation of butane-l ,3-diene to butane.
C
4
H
6
(
g
)
+
2
H
2
(
g
)
→
C
4
H
10
(
g
)
Δ
r
H
°
=
?
[Hint: Write equations for the combustion reactions. In each combustion, the products are
C
O
2
(
g
)
and
H
2
O
(
I
)
.
]
The standard heat of combustion of liquid cyclopentane, C5H10(l),C5H10(l), was measured to be −3291.6 kJ/mol.−3291.6 kJ/mol. What is Δ^H∘f C5H10(l),ΔH^f C5H10(l)∘, the standard heat of formation of liquid cyclopentane?
The standard enthalpies of formation of gaseous propyne (C3H4), propylene (C3H6), and propane (C3H8) are +185.4, +20.4 , and -103.8kJ/mol,
Calculate the heat evolved per mole on combustion of each substance to yield CO2(g) and H2O(g).
Calculate the heat evolved on combustion of 1 kg of each substance.
3. Which is the most efficient fuel in terms of heat evolved per unit mass?
The enthalpy of neutralization of a newly discovered compound, J(OH)3, was determined using a styroball calorimeter. The calorimeter was first calibrated using 13.00 mL of 0.104 M NaOH and 11.29 mL of 0.125 M HCl (ΔH = -55.85 kJ/mol) and a temperature rise of 4.6 °C was recorded. Using the same calorimeter, 7.58 mL of 0.151 M of J(OH)3 was reacted with 9.60 mL of 0.125 M HCl and the temperature changed from 25.9 °C to 23.4 °C. a. What is the heat capacity of the calorimeter? b. Write the balanced chemical equation for the reaction between J(OH)3 and HCl.c. Identify the limiting reactant in the reaction between J(OH)3 and HCl. d. What is the enthalpy of the reaction of J(OH)3 and HCl?
Chapter 7 Solutions
General Chemistry: Principles and Modern Applications, Loose Leaf Version (11th Edition)
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Calorimetry Concept, Examples and Thermochemistry | How to Pass Chemistry; Author: Melissa Maribel;https://www.youtube.com/watch?v=nSh29lUGj00;License: Standard YouTube License, CC-BY