How many oxygen atoms are present in MgSO4 • 7H2O?

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Chemistry, The Central Science, 11th edition
Theodore L. Brown; H. Eugene LeMay, Jr.;
Bruce E. Bursten and Catherine J. Murphy
Chapter 5
Thermochemistry
Donna Narsavage Heald
Siena College
Loudonville, NY
 2009, Prentice-Hall
Which metal will undergo the greatest
temperature change if an equal amount
of heat is added to each?
1.
2.
3.
4.
5.
Fe, s = 0.45 J/g K
Al, s = 0.90 J/g K
Cu, s = 0.38 J/g K
Pb, s = 0.13 J/g K
Sn, s = 0.22 J/g K
Which metal will undergo the greatest
temperature change if an equal amount
of heat is added to each?
1.
2.
3.
4.
5.
Fe, s = 0.45 J/g K
Al, s = 0.90 J/g K
Cu, s = 0.38 J/g K
Pb, s = 0.13 J/g K
Sn, s = 0.22 J/g K
If a piece of metal at 85°C is added to water at
25°C, the final temperature of the system is 30°C.
Which of the following is true?
1.
2.
3.
4.
5.
Heat lost by the metal > heat gained by water.
Heat gained by water > heat lost by the metal.
Heat lost by metal > heat lost by the water.
Heat lost by the metal = heat gained by water.
More information is required.
If a piece of metal at 85°C is added to water at
25°C, the final temperature of the system is 30°C.
Which of the following is true?
1.
2.
3.
4.
5.
Heat lost by the metal > heat gained by water.
Heat gained by water > heat lost by the metal.
Heat lost by metal > heat lost by the water.
Heat lost by the metal = heat gained by water.
More information is required.
Which reaction represents the DHf reaction
for NaNO3?
1.
2.
3.
4.
5.
Na+ (aq) + NO3- (aq)
NaNO3 (aq)
Na+ (g) + NO3- (g)
NaNO3 (s)
Na (s) + NO3 (s)
NaNO3 (s)
2 Na (s) + N2 (g) + 3 O2 (g)
2 NaNO3 (s)
2 Na (s) + 1/2 N2 (g) + 3/2 O2 (g)
NaNO3 (s)
Which reaction represents the DHf reaction
for NaNO3?
1.
2.
3.
4.
5.
Na+ (aq) + NO3- (aq)
NaNO3 (aq)
Na+ (g) + NO3- (g)
NaNO3 (s)
Na (s) + NO3 (s)
NaNO3 (s)
2 Na (s) + N2 (g) + 3 O2 (g)
2 NaNO3 (s)
2 Na (s) + 1/2 N2 (g) + 3/2 O2 (g)
NaNO3 (s)
Which of the following statements is true
for the diagram?
1.
2.
3.
4.
5.
Internal energy > 0
Internal energy < 0
Enthalpy > 0
Enthalpy < 0
Internal energy = enthalpy
System
Surroundings
heat
work
Which of the following statements is true
for the diagram?
1.
2.
3.
4.
5.
Internal energy > 0
Internal energy < 0
Enthalpy > 0
Enthalpy < 0
Internal energy = enthalpy
System
Surroundings
heat
work
What is the value of the
unknown DH in the diagram?
1.
2.
3.
4.
5.
+329.5 kJ
–329.5 kJ
+285.8 kJ
–241.8 kJ
+241.8 kJ
DH = –285.8 kJ
H2 (g) + 1/2 O2 (g)
DH = ?
H2O (g)
DH = –44.0 kJ
H2O (l)
What is the value of the
unknown DH in the diagram?
1.
2.
3.
4.
5.
+329.5 kJ
–329.5 kJ
+285.8 kJ
–241.8 kJ
+241.8 kJ
DH = –285.8 kJ
H2 (g) + 1/2 O2 (g)
DH = ?
H2O (g)
DH = –44.0 kJ
H2O (l)

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