Chemistry Straighterline Exam |
Questions Answered 100%
Correct/Verified Solutions
Calculate the enthalpy change for the reaction:
C(graph) + 2H2(g) + 1/2O2(g) CH3OH(l)
Using the following information:
C(graph) + O2 CO2(g) ΔHof = ─393.5 kJ.
H2(g) + 1/2O2 H2O(l) ΔHof = ─285.8 kJ.
CH3OH(l) + 3/2O2(g) CO2(g) + 2H2O(l) ΔHorxn = ─726.4 kJ
A. ─1691.5 kJ B. ─238.7 kJ C. 1691.5 kJ D. 47.1 kJ E. ─47.1 kJ - ANSWER B
Calculate the enthalpy change for the reaction:
2C8H18(l) + 17O2(g) 16CO(g) + 18H2O(l) ΔHorxn = ?
Given:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn = ─11,020 kJ.
2CO(g) + O2(g) 2CO2(g) ΔHof = ─566.0 kJ.
A. 10.450 MJ B. 6.492 MJ C. 15.550 MJ D. ─6.492 MJ E. ─10.450 MJ - ANSWER D
Calculate the enthalpy change for the reaction:
2C8H18(l) + 21O2(g) 8CO(g) + 8CO2(g) + 18H2O(l) ΔHorxn = ?
Given:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn = ─11,020 kJ.
2CO(g) + O2(g) 2CO2(g) ΔHof = ─566.0 kJ.
A. 1.0454 104 kJ B. ─8756 kJ C. 1.1586 104 kJ D. ─6,492 kJ
E. ─1.0454 104 kJ - ANSWER B
,Given the thermochemical equation:
2SO2 + O2 2SO3 ΔHorxn = ─198 kJ.
What is the enthalpy change (ΔHo) for the decomposition of one mole of
SO3? A. 198 kJ B. ─99 kJ C. 99 kJ D. 396 kJ E. ─198 kJ - ANSWER C
Given:
H2(g) + 1/2O2(g) H2O(l) ΔHof = ─286 kJ
What is the enthalpy change for the following reaction?
2H2O(l) 2H2(g) + O2(g) ΔHorxn = ?
A. ΔHo = ─286 kJ
B. ΔHo = +286 kJ
C. ΔHo = ─572 kJ
D. ΔHo = +572 kJ
E. ΔHo = ─143 kJ - ANSWER D
A home aquarium is an example of an open system - ANSWER TRUE
In an endothermic process heat is absorbed by the system. - ANSWER TRUE
The heat absorbed by a system at constant pressure is equal to ΔE + PΔV. - ANSWER TRUE
The work done on the surroundings by the expansion of a gas is w = ─PΔV. - ANSWER TRUE
The heat capacity of 20.0 g of water is 83.7 J/oC. - ANSWER TRUE
If 2Mg(s) + O2(g) 2MgO(s) ΔHo = ─1203.6 kJ; then for Mg(s) + 1/2O2(g) MgO(s)
,the enthalpy change is ΔHf = ─601.8 kJ - ANSWER TRUE
Chemical reactions in a bomb calorimeter occur at constant pressure
Conditions. - ANSWER FALSE
The specific heats of water and iron are 4.184 and 0.444 J/g•oC, respectively.
When equal masses of water and iron both absorb the same amount of heat, the temperature
increase of the water will be 5.42 times greater than that of the iron. - ANSWER FALSE
Pentaborane B5H9(s) burns vigorously in O2 to give B2O3(s) and H2O(l). Write and balance the
combustion equation. Calculate the ΔHorxn for the combustion of 1 mol of B5H9 given the
following enthalpies of formation.
ΔHof[B2O3(s)] = ─1273.5 kJ/mol
ΔHof[B5H9(s)] = 73.2 kJ/mol
ΔHof[H2O(l)] = ─285.8 kJ/mol
A. ─1.2735 MJ
B. ─4.543 MJ
C. ─18.170 MJ
D. ─9.086 MJ
E. ─8.448 MJ - ANSWER B
For the reaction:
C(s) + O2(g) CO2(g) ΔHof = ─393 kJ
How many grams of C(s) must be burned to release 275 kJ of heat?
A. 22.3 g B. 0.70 g C. 12.0 g D. 17.1 g E. 8.40 g - ANSWER E
, The combustion of butane produces heat according to the equation:
2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O(l) ΔHorxn = ─5,314 kJ
What is the heat of combustion per gram of butane?
A. -32.5 kJ B. -45.7 kJ C. -91.5 kJ D. -2,656 kJ E. -15,440 kJ - ANSWER B
The combustion of octane produces heat according to the equation:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn= ─11,020 kJ What
is the heat of combustion per gram of octane?
A. 5.510 MJ B. 96.5 kJ C. 48.2 kJ D. 193 kJ E. 629.2 MJ - ANSWER C
The combustion of butane produces heat according to the equation:
2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O(l) ΔHorxn= ─5314 kJ
How many grams of butane must be burned to release 6375 kJ of heat?
A. 1.20 g B. 139 g C. 0.0413 g D. 69.7 g E. 97.8 g - ANSWER B
Given the following information:
CaO(s) + H2O(l) Ca(OH)2(s) ΔHorxn = ─64.8 kJ/mol
How many grams of CaO must react in order to liberate 525 kJ of heat?
A. 6.92 g B. 56.1 g C. 455 g D. 606 g E. 3.40 104 g - ANSWER C
The combustion of pentane produces heat according to the equation:
C5H12(l) + 8O2(g) 5CO2(g) + 6H2O(l) ΔHorxn= ─3510 kJ
How many grams of CO2 are produced per 2500 kJ of heat released?
A. 0.0809 g B. 3.56 g C. 31.3 g D. 157 g E. 309 g - ANSWER D
The combustion of butane produces heat according to the equation:
Questions Answered 100%
Correct/Verified Solutions
Calculate the enthalpy change for the reaction:
C(graph) + 2H2(g) + 1/2O2(g) CH3OH(l)
Using the following information:
C(graph) + O2 CO2(g) ΔHof = ─393.5 kJ.
H2(g) + 1/2O2 H2O(l) ΔHof = ─285.8 kJ.
CH3OH(l) + 3/2O2(g) CO2(g) + 2H2O(l) ΔHorxn = ─726.4 kJ
A. ─1691.5 kJ B. ─238.7 kJ C. 1691.5 kJ D. 47.1 kJ E. ─47.1 kJ - ANSWER B
Calculate the enthalpy change for the reaction:
2C8H18(l) + 17O2(g) 16CO(g) + 18H2O(l) ΔHorxn = ?
Given:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn = ─11,020 kJ.
2CO(g) + O2(g) 2CO2(g) ΔHof = ─566.0 kJ.
A. 10.450 MJ B. 6.492 MJ C. 15.550 MJ D. ─6.492 MJ E. ─10.450 MJ - ANSWER D
Calculate the enthalpy change for the reaction:
2C8H18(l) + 21O2(g) 8CO(g) + 8CO2(g) + 18H2O(l) ΔHorxn = ?
Given:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn = ─11,020 kJ.
2CO(g) + O2(g) 2CO2(g) ΔHof = ─566.0 kJ.
A. 1.0454 104 kJ B. ─8756 kJ C. 1.1586 104 kJ D. ─6,492 kJ
E. ─1.0454 104 kJ - ANSWER B
,Given the thermochemical equation:
2SO2 + O2 2SO3 ΔHorxn = ─198 kJ.
What is the enthalpy change (ΔHo) for the decomposition of one mole of
SO3? A. 198 kJ B. ─99 kJ C. 99 kJ D. 396 kJ E. ─198 kJ - ANSWER C
Given:
H2(g) + 1/2O2(g) H2O(l) ΔHof = ─286 kJ
What is the enthalpy change for the following reaction?
2H2O(l) 2H2(g) + O2(g) ΔHorxn = ?
A. ΔHo = ─286 kJ
B. ΔHo = +286 kJ
C. ΔHo = ─572 kJ
D. ΔHo = +572 kJ
E. ΔHo = ─143 kJ - ANSWER D
A home aquarium is an example of an open system - ANSWER TRUE
In an endothermic process heat is absorbed by the system. - ANSWER TRUE
The heat absorbed by a system at constant pressure is equal to ΔE + PΔV. - ANSWER TRUE
The work done on the surroundings by the expansion of a gas is w = ─PΔV. - ANSWER TRUE
The heat capacity of 20.0 g of water is 83.7 J/oC. - ANSWER TRUE
If 2Mg(s) + O2(g) 2MgO(s) ΔHo = ─1203.6 kJ; then for Mg(s) + 1/2O2(g) MgO(s)
,the enthalpy change is ΔHf = ─601.8 kJ - ANSWER TRUE
Chemical reactions in a bomb calorimeter occur at constant pressure
Conditions. - ANSWER FALSE
The specific heats of water and iron are 4.184 and 0.444 J/g•oC, respectively.
When equal masses of water and iron both absorb the same amount of heat, the temperature
increase of the water will be 5.42 times greater than that of the iron. - ANSWER FALSE
Pentaborane B5H9(s) burns vigorously in O2 to give B2O3(s) and H2O(l). Write and balance the
combustion equation. Calculate the ΔHorxn for the combustion of 1 mol of B5H9 given the
following enthalpies of formation.
ΔHof[B2O3(s)] = ─1273.5 kJ/mol
ΔHof[B5H9(s)] = 73.2 kJ/mol
ΔHof[H2O(l)] = ─285.8 kJ/mol
A. ─1.2735 MJ
B. ─4.543 MJ
C. ─18.170 MJ
D. ─9.086 MJ
E. ─8.448 MJ - ANSWER B
For the reaction:
C(s) + O2(g) CO2(g) ΔHof = ─393 kJ
How many grams of C(s) must be burned to release 275 kJ of heat?
A. 22.3 g B. 0.70 g C. 12.0 g D. 17.1 g E. 8.40 g - ANSWER E
, The combustion of butane produces heat according to the equation:
2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O(l) ΔHorxn = ─5,314 kJ
What is the heat of combustion per gram of butane?
A. -32.5 kJ B. -45.7 kJ C. -91.5 kJ D. -2,656 kJ E. -15,440 kJ - ANSWER B
The combustion of octane produces heat according to the equation:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn= ─11,020 kJ What
is the heat of combustion per gram of octane?
A. 5.510 MJ B. 96.5 kJ C. 48.2 kJ D. 193 kJ E. 629.2 MJ - ANSWER C
The combustion of butane produces heat according to the equation:
2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O(l) ΔHorxn= ─5314 kJ
How many grams of butane must be burned to release 6375 kJ of heat?
A. 1.20 g B. 139 g C. 0.0413 g D. 69.7 g E. 97.8 g - ANSWER B
Given the following information:
CaO(s) + H2O(l) Ca(OH)2(s) ΔHorxn = ─64.8 kJ/mol
How many grams of CaO must react in order to liberate 525 kJ of heat?
A. 6.92 g B. 56.1 g C. 455 g D. 606 g E. 3.40 104 g - ANSWER C
The combustion of pentane produces heat according to the equation:
C5H12(l) + 8O2(g) 5CO2(g) + 6H2O(l) ΔHorxn= ─3510 kJ
How many grams of CO2 are produced per 2500 kJ of heat released?
A. 0.0809 g B. 3.56 g C. 31.3 g D. 157 g E. 309 g - ANSWER D
The combustion of butane produces heat according to the equation:
