# chem urgent!

Set up a Hess's law cycle, and use the following information to calculate ÄH°f for aqueous nitric acid, HNO3(aq). You will need to use fractional coefficients for some equations.

3 NO2(g) + H2O(l) 2 HNO3(aq) + NO(g) ÄH° = -138.4 kJ
2 NO(g) + O2(g) 2 NO2(g) ÄH° = -114 kJ
4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(l) ÄH° = -1169.6 kJ
NH3(g) ÄH°f = -46.1 kJ/mol
H2O(l)

1. 0
2. 0
3. 2
1. Where does the H2O(l) by itself at the bottom of your post fit in?

1. 0
2. 0
posted by DrBob222
2. the h2o is

ÄH°f = -285.8 kJ/mol

1. 0
2. 0
posted by rebekah

## Similar Questions

1. ### Chem

Set up a Hess’s law cycle, and use the following information to calculate ΔH∘f for aqueous nitric acid, HNO3(aq). You will need to use fractional coefficients for some equations. 3NO2(g)+H2O(l)→2HNO3(aq)+NO(g) ΔH∘ =
2. ### chemistry

Hess¡¯ law says that when we add reactions together we can also add the enthalpies. Given the following set of reactions, use Hess¡¯ Law to calculate the enthalpy of the reaction given below. N2H4 + H2 ¡æ 2 NH3 ¥ÄH¡Æ = ?
3. ### chem expirement!

You are required to design an experiment to test Hess's law using the combustion of ethanol. Write a brief design for this experiment. What I wrote as my answer: Hess’ Law: is the algebraic addition of chemical equations yields
4. ### chem experiment:

You are required to design an experiment to test Hess's law using the combustion of ethanol. Write a brief design for this experiment. What I wrote as my answer: Hess’ Law: is the algebraic addition of chemical equations yields
5. ### chemistry

17. Calculate H for the following reaction using Hess law H2 (g) + Br2 (g) → 2 HBr (g) Experimental information 2 H+ → H2 H -436.4 kJ 2 Br- → Br2 H -192.5 kJ 2 H+ + 2 Br- →2 HBr H -144.8 kJ
6. ### chemistry

18. Calculate ƒ´H for the following reaction using Hess law H2 (g) + Br2 (g) ¡÷ 2 HBr (g) Experimental information 2 H+ ¡÷ H2 ƒ´H -436.4 kJ 2 Br- ¡÷ Br2 ƒ´H -192.5 kJ 2 H+ + 2 Br- ¡÷2 HBr ƒ´H -144.8 kJ
7. ### chemistry

At 25 C the following heats of reaction are known: 2CIf (g)+ O2(g) -> CL2O (g) + f2O Delta H rxn= 167.4 kj/mol 2CIf3(g) + 2O2 (g)-> Cl2O(g) + 3F2O(g) Delta H rxn= 341.4 2F2(g) + O2(g) -> 2F2O(g) Delta H rxn= -43.4kj/mol at the
8. ### Chemistry VERY URGENT PLEASE

A) NaOH(s) > NaOH(aq) B) NaOH(s) + HCl(aq) > NaCl(aq) + H2O(l) C) NaOH(aq) + HCl(aq) > NaCl(aq) + H2O(l) Examine the 3 reaction equations, and determine the relationship between them. Demonstrate this relationship by combining the
9. ### chemistry

17. Calculate ƒ´H of strontium carbonate using Hess law Sr + C (graphite) + 3/2 O2 ¡÷ SrCO3 Experimental information SrO ¡÷ Sr + 1/2 O2 ƒ´H 592 kJ SrO + CO2 ¡÷ SrCO3 ƒ´H -234 kJ 2 C (graphite) + 2 O2 ¡÷ 2 CO2 ƒ´H
10. ### Chemistry

Use Hess' Law to calculate the heat of the following equation. Show all work including the reactions that you use, in the form that you use them. 2 C + 2 NO2 ---> 2 CO 2 + N 2

More Similar Questions