HomeworkLib
Question

(6 pts.) Using Hess’s Law and the values for Standard Enthalpies of Formation from the table...

(6 pts.) Using Hess’s Law and the values for Standard Enthalpies of Formation from the table provided, calculate the enthalpy of reaction ΔH°rxn (in kJ) for each of the following reactions:

Standard Enthalpies of Formation

substance

ΔHf° in kJ/mol

Mg(s)

0

MgO(s)

-601.6

HCl(aq)

-167.2

MgCl2(aq)

-801.2

H2(g)

0

H2O(l)

-285.8

Reaction #1: Mg (s) + 2HCl (aq) è MgCl2 (aq) + H2 (g)

Reaction #2: MgO (s) + 2HCl (aq) è MgCl2 (aq) + H2O (l)

2. (4 pts.) Now use your calculated ΔH°rxn for the first reaction to predict the amount of heat energy that would be transferred between the system and the surroundings if 0.250 g of Mg were to react with an excess of HCl(aq). Express your answer as a value of qp (heat transferred at constant pressure) with appropriate sign and units.

science   chemistry   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

0 0
Add a comment
Know the answer?
Add Answer to:
(6 pts.) Using Hess’s Law and the values for Standard Enthalpies of Formation from the table...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions

  • Applying Hess’s Law, from the enthalpies of reactions, 2NaCl(s) + H2O(l) --> 2HCl(g) + Na2O(s) ΔH...

    Applying Hess’s Law, from the enthalpies of reactions, 2NaCl(s) + H2O(l) --> 2HCl(g) + Na2O(s) ΔH = + 507.31 kJ NO(g) + NO2(g) + Na2O(s) --> 2NaNO2(s) ΔH = − 427.14 kJ NO(g) + NO2(g) --> N2O(g) + O2(g) ΔH = − 42.68 kJ 2HNO2(l) --> N2O(g) + O2(g) + H2O(l) ΔH = + 34.35 kJ Calculate the enthalpy change (ΔHrxn) for the reaction: HCl(g) + NaNO2(s) --> HNO2(l) + NaCl(s) (You should show work to get credit) 5-Magnesium burns...

  • Using the table of standard entropies and enthalpies of formation, calculate AH°, ASº, and AG° for...

    Using the table of standard entropies and enthalpies of formation, calculate AH°, ASº, and AG° for the following reactions at 298.15 K. (Use only the table of standard entropies and standard enthalpies of formation, not the table of standard Gibbs free energies.) kJ AH; () AS; mol-K mol Compound C(s) 5.7 CO(g) -110.5 197.7 The equation SiO2(s) + 2 Mg(s) Si(s) + 2 CO2(g) -393.5 213.8 MgO(s) C2(g) 223.1 H2(g) 130.7 • AH° kJ HCl(g) 186.9 -92.3 • AS° MK...

  • a) Using the Hess Law and the thermochemical equations below,      MgO(s)   +   + 2HCl(aq)   ------>...

    a) Using the Hess Law and the thermochemical equations below,      MgO(s)   +   + 2HCl(aq)   ------> MgCl2(g)   + H2O(l)         ΔHrxn = -111.7 kJ/mol            Mg(s)    + 2 HCl(aq)     ------>      MgCl2(g)   + H2(g)         ΔHrxn = -548.3 kJ/mol      H2(g)    + 1/2 O2(g)     ------>      H2O(l)          ΔHrxn = -142.9 kJ/mol find the heat of reaction of the following:            Mg(s)    + 1/2 O2(g)     ------>      MgO(g)      ΔHrxn =   ? b) If the theoretical enthalpy of this reaction is -602 kJ/mol, calculate the percent error

  • Using the Hess Law and the thermochemical equations below,      MgO(s)   +   + 2HCl(aq)   ------> MgCl2(g)  ...

    Using the Hess Law and the thermochemical equations below,      MgO(s)   +   + 2HCl(aq)   ------> MgCl2(g)   + H2O(l)         ΔHrxn = -111.7 kJ/mol            Mg(s)    + 2 HCl(aq)     ------>      MgCl2(g)   + H2(g)         ΔHrxn = -548.3 kJ/mol      H2(g)    + 1/2 O2(g)     ------>      H2O(l)          ΔHrxn = -142.9 kJ/mol find the heat of reaction of the following: (0.25 pt.)          Mg(s)    + 1/2 O2(g)     ------>      MgO(g)      ΔHrxn =   ? b) If the theoretical enthalpy of this reaction is -602 kJ/mol,...

  • Question 17 3 pts Using standard molar enthalpies of formation given in the table below, calculate...

    Question 17 3 pts Using standard molar enthalpies of formation given in the table below, calculate AH/xnto one decimal place, for the combustion of ammonia: AHrxn° = E nAH (products) - E mAHt"reactants) 4 NH3(g) + 7 O2(g) → 4NO2(g) + 6H2O(1) molecule AHF (kJ/mol-rxn) NH3(g) -45.9 NO2(g) +33.1 H2O(1) -285.8 H2O(9) -241.8 - 1663.6 kJ/mol-rxn +30.24 kJ/mol-rxn -1398.8 kJ/mol-rxn -298.6 kJ/mol-rxn -206.9 kJ/mol-rxn Question 11 3 pts A gas absorbs 45 kJ of heat and does 29 kJ of...

  • Magnesium chloride hexahydrate (MgCl2·6H2O) can be prepared by the following reaction: MgO(s) + 2HCl(aq) + 5H2O(l)...

    Magnesium chloride hexahydrate (MgCl2·6H2O) can be prepared by the following reaction: MgO(s) + 2HCl(aq) + 5H2O(l) ⟶ MgCl2∙6H2O(s) ΔH°rxn = -133 kJ/mol What is the standard molar enthalpy of formation of magnesium chloride hexahydrate in kJ/mol? ΔH°f(MgO)=-602 kJ/mol ΔH°f(HCl)=-167 kJ/mol ΔH°f(H2O)=-286 kJ/mol a) -1444 b) -133 c) -2499

  • Part III. Use of Hess's Law to Determine the Heat of Formation of Magnesium Oxide Write...

    Part III. Use of Hess's Law to Determine the Heat of Formation of Magnesium Oxide Write in the average molar heats of reaction for the reaction of magnesium with hydrochloric acid and the reaction of magnesium oxide with hydrochloric acid. Make a Hess's Law calculation in the space provided below, using the heats of reaction of magnesium and magnesium oxide and the heat of formation of water, to calculate the heat of reaction for the reaction Mg(s) + 1/2 O2...

  • 4. Calculate the energy change for the following reaction, using the standard enthalpies of formation provided....

    4. Calculate the energy change for the following reaction, using the standard enthalpies of formation provided. SO2Cl2 (I)+2 H2O (I)2 HCI (g) + H,SO4 ) Substance AH (/mol) SO-ClO H2O0) HO(g) НСКО НС 9) H2SO 0) H-SO (aq) -394.1 -285.8 -241.8 92.3 -167.2 814.0 -909.3 If 25.0 kJ of heat energy is added to 50.0 g of water initially at 25°C, what will be the final temperature of the water? The specific heat of water is 4.18 J g1 °C

  • 1).From the standard enthalpies of formation, calculate ΔH°rxn for the reaction C6H12(l) + 9O2(g) → 6CO2(g)...

    1).From the standard enthalpies of formation, calculate ΔH°rxn for the reaction C6H12(l) + 9O2(g) → 6CO2(g) + 6H2O(l) For C6H12(l), ΔH°f = –151.9 kJ/mol (5 points) Substance ∆H°f , kJ/mol C6H12(l) –151.9 O2(g) 0 H2O(l) –285.8 CO2(g) –393.5 2).Determine the amount of heat (in kJ) given off when 1.26 × 104 g of ammonia are produced according to the equation N2(g) + 3H2(g) → 2NH3(g)       ΔH°= –92.6 kJ/mol Assume that the reaction takes place under standard conditions at 25oC.

  • Part A - Calculating an Enthalpy of Reaction from Enthalpies of Formation Calculate the enthalpy change...

    Part A - Calculating an Enthalpy of Reaction from Enthalpies of Formation Calculate the enthalpy change for the reaction: 2 H2O2(l) → 2 H2O(l) + O2(g) using enthalpies of formation: ΔH∘f[H2O2]ΔH∘f[H2O]==−187.8 kJ/mol−285.8 kJ/mol Calculate the enthalpy change for the reaction: using enthalpies of formation: Multiple choice answers below: -98.0 kJ -196.0 kJ +98.0 kJ +196.0 kJ

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT