Hess’s Law

Welcome to the Hess’s Law category on Questions LLC! If you're interested in understanding and exploring the principles of Hess’s Law, you've come to the right place. This category is dedicated to answering all your questions about Hess’s Law, a fundamental concept in thermodynamics. Whether you're a student studying chemistry or simply curious about how energy changes during chemical reactions, we aim to provide clear explanations and insightful answers to help deepen your understanding of this intriguing topic. Browse through the questions and find explanations that clarify the intricacies of Hess’s Law, enabling you to grasp its significance in various chemical processes.

Questions (58)

DrBob222 PLEASE HELPHf of CO2 = -393.5 kJ/mol Hf of H2O = -285.8 kJ/mol The combustion reaction for benzoic acid C6H5CO2H(s) +
1. 5 answers
2. asked by Rachel M
3. 2,362 views
Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g) delta H1?MgO(s) + 2HCl(aq) ->MgCl2(aq) + H2O(l) delta H2? To make these equations add up
1. 5 answers
2. asked by Hannah
3. 5,733 views
I've attempted this problem but not sure if i'm on the right track.Use the enthalpy diagram provided above and apply Hess’s
1. 1 answer
2. asked by Vince
3. 739 views
2. (a) Given the following equations and H0rxn at 250CH3BO3(aq) �¨ HBO2(aq) + H2O(l) ∆H0rxn = -0.02kJ H2B4 O7(s) + H2O(l)
1. 2 answers
2. asked by ceasar3
3. 510 views
Using Hess law, calculate ΔH for the equation: O3 (g) +2NO2 (g)→ N2O5 (g) + O2 (g)Given the following equations: N2O5 (g)
1. 2 answers
2. asked by ezile
3. 126 views
Using Hess law, calculate ΔH for the equation: N2O3 ---> NO + NO2N2O3 ---> N2 + 3⁄2O2 ΔH = 83.7 kJ 1⁄2N2 + 1⁄2O2 ---> NO
1. 2 answers
2. asked by ezile
3. 75 views
Given the following data:MnO(s) + H2(g) Mn(s) + H2O(l), H = 100 kJ MnO2(s) + 2 H2(g) Mn(s) + 2 H2O(l), H = 52 kJ use
1. 4 answers
2. asked by Ari
3. 1,532 views
Given that:H2 (g) + F2 (g) ---> 2HF (g) H(rxn)= -546.6 kJ 2H2 (g) + O2 (g) ---> 2H2O (l) H (rxn)= -571.6 kJ calculate the value
1. 4 answers
2. asked by Chelsea
3. 2,342 views
Calculate delta H for the reaction below using Hess's Law:C2H6 ---> C2H2 + 2H2 ------------------------------------------ C2H2 +
1. 4 answers
2. asked by Gabby
3. 4,527 views
Using data from the following reactions and applying Hess's law, calculate the heat change for the slow reaction of zinc with
1. 3 answers
2. asked by Amanda
3. 1,622 views
How do I use Hess's law to calculate enthalpy change? (when given two reactions)(1)Pb(s) + Cl2(g) --> PbCl2(s) Delta H(1)=
1. 3 answers
2. asked by Emma
3. 820 views
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
1. 3 answers
2. asked by Finn
3. 2,134 views
17. Calculate H for the following reaction using Hess lawH2 (g) + Br2 (g) → 2 HBr (g) Experimental information 2 H+ → H2
1. 3 answers
2. asked by john
3. 1,129 views
Given the following thermochemical data:H2O(l)+2AgNO3(aq) ¡æ 2HNO3(aq)+Ag2O(s) ¥ÄH = 44.8 kJ 2Ag(s)+¨öO2(g) ¡æ Ag2O(s)
1. 3 answers
2. asked by Help?
3. 852 views
consider the following changes at constant temperature & pressureH2O(s) --yields-- H20(l); Delta H1 H2O(l) --yields-- H2O(g);
1. 3 answers
2. asked by marcus
3. 1,950 views
Consider the gas-phase transfer of an electron from a sodium atom to a chlorine atom:Na(g)+Cl(g)-->Na^(+)(g)+Cl^(-)(g) I was
1. 4 answers
2. asked by Ezra
3. 727 views
if enthalpies for formation of p4o10, h2o and h3po4 are -2984, -285.9 and -1279 respectively calculate the enthalpy change using
1. 2 answers
2. asked by mala
3. 995 views
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
1. 3 answers
2. asked by Court
3. 1,640 views
The four statements below are used for applications of Hess's law. One of the statements is erroneous. Choose that statement.a)
1. 3 answers
2. asked by Hannah
3. 1,337 views
Hess's law ____.A) makes it possible to calculate ΔH for complicated chemical reactions B) states that when you reverse a
1. 2 answers
2. asked by Samantha Taylor Greenfield
3. 928 views
(1) 2 Ni(s) + O2 (g) --> 2NiO(s) delta H= -479.4 kJ(2) Ni(s) + Cl2(g) --> NiCl2(s) delta H= -305.3 kJ Using equations 1 and 2
1. 1 answer
2. asked by Brian
3. 658 views
Im doing a worksheet and i had to draw PE diagram which had the Ea(activation energy)at 80kJ and the enthalpy change is -40kJ.*A
1. 1 answer
2. asked by Anonymous
3. 1,037 views
Set up a Hess's law cycle, and use the following information to calculate ÄH°f for aqueous nitric acid, HNO3(aq). You will
1. 3 answers
2. asked by hannah
3. 742 views
Use Hess's law and the reactions1) CH 4(g)+ Cl 2 (g)--->CH 3 CL(g) + HCl (g) 2) CH 3 Cl (g) + Cl 2 (g)---> CH 2 Cl 2 (g) + HCl
1. 2 answers
2. asked by Jessica Jones
3. 794 views
Use Hess's Law to find ΔH for the following reactions: Express your answers in kJ/mol of the first reactant on the left in each
1. 3 answers
2. asked anonymously
3. 49 views
Use Hess's Law to find ΔH for the following reactions: Express your answers in kJ/mol of the first reactant on the left in each
1. 5 answers
2. asked anonymously
3. 47 views
Help me! Express your answers in kJ/mol!!Use Hess's Law to find ΔH for the following reactions: Express your answers in kJ/mol
1. 4 answers
2. asked anonymously
3. 37 views
You are required to design an experiment to test Hess's law using the combustion of ethanol. Write a brief design for this
1. 1 answer
2. asked by rob
3. 684 views
This is a Hess' Law problem. I think I got it but I'm hoping you could check it for me:Calculate the heat of reaction for
1. 1 answer
2. asked by Belinda
3. 1,167 views
The amount of heat evolved or absorbed during chemical reaction is independent of the path by which the change has taken place,
1. 7 answers
2. asked anonymously
3. 51 views
If you need to multiply the following reaction by 2 to be an intermediate reaction in a Hess's law problem, what would be the
1. 6 answers
2. asked by Anonymous
3. 6,059 views
Calculate the enthalpy change for the reaction 2C (s) + H2 (g) yield C2H2 (g) given the following reactions and their respective
1. 3 answers
2. asked by Lucy
3. 4,123 views
What is the process to calculate ΔH° for the reaction?O2(g) + 2NO(g) --> N2O4(g) O2(g) + 2NO(g) --> 2NO2(g) ΔH°1 N2O4(g) -->
1. 4 answers
2. asked by Anonymous
3. 4,051 views
Find the enthalpy for : 4Fe + 3O2 = 2Fe2O3I got the following informations: Fe + 3H2O = Fe(OH)3 + 3/2H2 - Enthalpy is 160.9 kj
1. 3 answers
2. asked by Shadow
3. 2,338 views
Can you please check my work? I got -4.3KJ/molIf this is not right can you tell me what I am doing wrong? Thank you! Questions.
1. 3 answers
2. asked by Lauren
3. 2,320 views
1.Hess's law _____. A.) makes it possible to calculate H for complicated chemical reactions B.) states that when you reverse a
1. 5 answers
2. asked by Jack
3. 2,016 views
Given the Data:N2(g) + O2g) = 2NO(g) delta H = 180.7kj, 2NO(g) + O2(g) = 2NO2(g) delta H = 0113.1kj, 2N2O(g) = 1N2(g) + O2(g)
1. 3 answers
2. asked by Brett
3. 2,010 views
Use Hess's law and the following equations to calculate ÄH for the reaction N2(g) + 2O2(g) N2O4(g).2NO2(g)->N2O4(g) ÄH =
1. 2 answers
2. asked by princess cunningham
3. 1,282 views
Hess's law _____.A.) makes it possible to calculate H for complicated chemical reactions B.) states that when you reverse a
1. 5 answers
2. asked by Jack
3. 1,244 views
Using Hess’s Law with the following data:N2(g) + O2(g) = 2NO(g) Del(H) = 180.7kj 2NO(g) + O2(g) = 2NO2(g) Del(H)= -113.1kj
1. 2 answers
2. asked by Dan
3. 1,118 views
Given the Data:N2(g) + O2g) = 2NO(g) delta H = 180.7kj, 2NO(g) + O2(g) = 2NO2(g) delta H = 0113.1kj, 2N2O(g) = 1N2(g) + O2(g)
1. 2 answers
2. asked by Dan
3. 1,117 views
Set up a Hess’s law cycle, and use the following information to calculate ΔH∘f for aqueous nitric acid, HNO3(aq). You will
1. 1 answer
2. asked by Meg
3. 1,023 views
In accordance with Hess�fs Law, manipulate the following equations and their ƒ¢Hrxn�fs to calculate ƒ¢Hrxn for the
1. 1 answer
2. asked by Angela
3. 944 views
Use Hess's law to calculate the enthalpy change for the reaction:3C(s) + 3H2(g) ¡æ C3H6(g) Given the following thermochemical
1. 2 answers
2. asked by Hailee
3. 945 views
Calculate the enthalpy change of formation for the following reactions using Hess's law, and the enthalpies of formation given
1. 2 answers
2. asked by BOB
3. 888 views
Use Hess's Law to find the change in heat of 2C(graphite)+H2(g)-->C2H2(g)?Given: C(graphite) + O2(g) --> CO2(g) change of heat
1. 1 answer
2. asked by Lauren
3. 719 views
How do I find the molar enthalpy H (kJ/mol) for reaction of NH3 + HCl -> NH4Cl at temp 9.8 celsius by using Hess's Law. I do not
1. 1 answer
2. asked by Natalie
3. 689 views
True or False: Hess's Law indicates that if there is an alternate path to run a chemical reaction, say in a series of steps, the
1. 3 answers
2. asked by Tae
3. 675 views
Which of the following is the best definition of Hess' Law?A. Heat is always released by the decomposition of 1 mole of a
1. 3 answers
2. asked by Anonymous
3. 658 views
18. Calculate ƒ´H for the following reaction using Hess lawH2 (g) + Br2 (g) ¡÷ 2 HBr (g) Experimental information 2 H+ ¡÷
1. 3 answers
2. asked by nona
3. 663 views

Hess’s Law

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