A 0.1326 g sample of magnesium was burned in an oxygen bomb calorimeter. The Htotal heat
capacity of the calorimeter plus water was 5760 J/oC. If the temperature rise of the
calorimeter with water was 0.570oC, calculate the enthalpy of combustion of magnesium.
Mg(s) + 1/2O2(g) MgO(s)
A. ─3280...
A 0.1326 g sample of magnesium was burned in an oxygen bomb calorimeter. The Htotal heat
capacity of the calorimeter plus water was 5760 J/oC. If the temperature rise of the
calorimeter with water was 0.570oC, calculate the enthalpy of combustion of magnesium.
Mg(s) + 1/2O2(g) MgO(s)
A. ─3280 kJ/mol B. ─24.8 kJ/mol C. 435 kJ/mol
D. 106 kJ/mol E. ─602 kJ/mol - ANSWER E
Which one of the following reactions occurring at 25oC does the symbol ΔHof[H2SO4(l)]
refer to?
A. 2H(g) + S(g) + 4O(g) H2SO4(l)
B. H2(g) + S(g) + 2O2(g) H2SO4(l)
C. H2SO4(l) H2(g) + S(s) + 2O2(g)
D. H2SO4(l) 2H(g) + S(s) + 4O(g)
E. H2(g) + S(s) + 2O2(g) H2SO4(l) - ANSWER E
Which one of the following reactions occurring at 25oC does the symbol ΔHof[HNO3(l)]
refer to?
A. H(g) + N(g) + O3(g) HNO3(l)
B. 1/2H2(g) + 1/2N2(g) + 3/2O2(g) HNO3(l)
C. HNO3(l) 1/2H2(g) + 1/2N2(g) + 3/2O2(g)
D. HNO3(l) H(g) + N(g) + 3O(g)
E. H2(g) + N2(g) + O3(g) HNO3(l) - ANSWER B
,When 0.56 g of Na(s) react with excess F2(g) to form NaF(s) at standard state conditions, 13.8
kJ of heat
are evolved. What is the standard enthalpy of formation (ΔHof) of NaF(s)?
A. 24.8 kJ/mol B. +570 kJ/mol C. ─24.8 kJ/mol D. ─7.8 kJ/mol
E. ─570 kJ/mol - ANSWER E
Ethanol undergoes combustion according to the equation:
C2H5OH(l) + O2(g) CO2(g) + H2O(l) (Not Balanced)
The standard heat of combustion of ethanol, C2H5OH(l), is ─1366.8 kJ/mol. Given that:
ΔHof[CO2(g)] = ─393.5 kJ/mol
ΔHof[H2O(l)] = ─285.8 kJ/mol
What is the standard enthalpy of formation of ethanol?
A. 3010 kJ
B. ─687.6 kJ
C. ─277.6 kJ
D. 687.6 kJ
E. 1367 kJ - ANSWER C
Find the standard enthalpy of formation of ethylene, C2H4(g), given the following data:
C2H4(g) + 3O2(g) 2CO2(g) + 2H2O(l) ΔHof = ─1411 kJ
C(s) + O2(g) CO2(g) ΔHof = ─393.5 kJ
H2(g) + 1/2O2(g) H2O(l) ΔHof = ─285.8 kJ
A. 52 kJ
B. 87 kJ
C. 731 kJ
D. 1.41 103 kJ
,E. 2.77 103 kJ - ANSWER A
Octane (C8H18) undergoes combustion according to the following thermochemical equation:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn = ─11,020 kJ.
Given that: ΔHof[CO2(g)] = ─393.5 kJ/mol
ΔHof[H2O(l)] = ─285.8 kJ/mol
Calculate the enthalpy of formation of 1 mole of octane.
A. ─210 kJ B. ─11,230 kJ C. 22,040 kJ D. ─420 kJ E. 420 kJ - ANSWER A
Glycine C2H5O2N is important for biological energy. The combustion of glycine is given by the
equation,
4C2H5O2N(s) + 9O2(g) 8CO2(g) + 10H2O(l) + 2N2(g) ΔHorxn = ─3857 kJ
Given that ΔHof[CO2(g)] = ─393.5 kJ/mol, and ΔHof[H2O(l)] = ─285.8 kJ/mol. Calculate
the enthalpy of formation ΔHof per mole of glycine.
A. ─537.2 kJ/mol
B. ─268.2 kJ/mol
C. 2149 kJ/mol
D. ─3178 kJ/mol
E. ─964 kJ/mol - ANSWER A
Calculate ΔHorxn for the following reaction.
2H2O2(l) 2H2O(l) + O2(g)
Use the following information:
ΔHof (H2O2(l)) = -187.6 kJ/mol ; ΔHof (H2O(l)) = -285.8 kJ/mol ; ΔHof (O2(g)) = 0
kJ/mol A. 53.0 kJ B. 98.2 kJ C. -98.2 kJ D. 196.4 kJ E. ─196.4 kJ - ANSWER E
Given 2Al(s) + 3/2O2(g) Al2O3(s) ΔHof = ─1670 kJ
What is ΔH for the reaction?
, 2Al2O3(s) 4Al(s) + 3O2(g) ΔHorxn = ?
A. 3340 kJ B. 1670 kJ C. ─3340 kJ D. ─1670 kJ E. ─835 kJ - ANSWER A
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
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:
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller KenAli. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $14.49. You're not tied to anything after your purchase.
