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December 20, 2014

Search: chemistry - hess's law (check + help)

Number of results: 63,095

Chemistry Hess's Law
(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 and Hess's Law, determine the amount of moles Nickel (ii) Chloride that was combusted given the following: volume = 15.45 L pressure = 2.29 atm...
October 23, 2013 by Brian

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 a net equation whose enthalpy of reaction is the ...
May 17, 2007 by rob

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 a net equation whose enthalpy of reaction is the ...
May 17, 2007 by rob

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 temperature, use Hess's Law to calculate ...
March 4, 2012 by Court

Chemistry
Explain why the calculated value for the (1) enthalpy of combustion for propane using bond energies (bond breaking and bond formation)might not be in close agreement to the values calculated using (2) Hess Law and the values calculated using the (3) summation of the change in ...
November 1, 2010 by Leah

chemistry - hess's law (check + help)
31. Carbon monoxide reacts with hydrogen gas to produce a mixture of methane, carbon dioxide, and water. (This mixture is known as substitute natural gas.) 4CO(g) + 8H2(g) → 3CH4(g) + CO2(g) + 2H2O(_) Use the following thermochemical equations to determine the enthalpy ...
June 8, 2011 by Farah

chemistry
if enthalpies for formation of p4o10, h2o and h3po4 are -2984, -285.9 and -1279 respectively calculate the enthalpy change using hess's law
July 4, 2012 by mala

chemistry
Use Hess's Law and a table of heats of formation to determine the enthalpy for the following reaction. 3SO2(g) + 3H2O(g) + 3/2O2(g) --->3H2SO4(l) ΔH = ?
September 28, 2014 by korko

chemistry
Use Hess's Law and a table of heats of formation to determine the enthalpy for the following reaction. 3SO2(g) + 3H2O(g) + 3/2O2(g) --->3H2SO4(l) ΔH = ?
September 28, 2014 by korko

Hess' law
Which of the following is the best definition of Hess' Law? A. Heat is always released by the decomposition of 1 mole of a compound into its constitute elements. B. Since enthalpy is a state function, it will be different if a reaction takes place in one step or a series of ...
February 9, 2007 by christine

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
April 24, 2011 by Kat

Chemistry
Hess's law _____. A.) makes it possible to calculate H for complicated chemical reactions B.) states that when you reverse a chemical equation, the sign of H does not change C.) determines the way a calorimeter works D.) describes the vaporization of solids Please help - I ...
March 4, 2013 by Jack

College Chemistry- Hess's Law
Nitrogen oxides undergo many interesting reactions in the environment and in industry. Given the following information, calculate H for the overall equation: 2 NO2(g) + 1/2 O2(g) = N2O5(s). 2 NO(g) + 3/2 O2(g) = N2O5(s), H = -223.7 kJ NO(g) + 1/2 O2(g) = NO2(g), H = -57.1 kJ
October 22, 2010 by Tahnee

Chemistry
1. Hess's law _____. A.) makes it possible to calculate H for complicated chemical reactions B.) states that when you reverse a chemical equation, the sign of H does not change C.) determines the way a calorimeter works D.) describes the vaporization of solids Please help me...
March 4, 2013 by Jack

Chemistry
What are the steps to solve this problem? "The enthalpies of combustion of glucose and ethanol are -2813kj/mol and -1369kj/mol, use Hess's law to calculate the enthalpy change when 0.500 kg of glucose is allowed to ferment." Please help.
November 28, 2014 by Julie

Chemistry
Calculate delta H for the reaction below using Hess's Law: C2H6 ---> C2H2 + 2H2 ------------------------------------------ C2H2 + 5/2O2 --> 2CO2 + H2O (H = -1300 kJ) 2H2 + O2 --> 2H2O (H= -572 kJ) 2C2H6 + 7O2 --> 4CO2 + 6H2O (H= -3120 kJ)
November 14, 2012 by Gabby

Chem
What is an experimental technique that could be used to determine the enthalpy of combustion of magnesium directly? Not using Hess's Law!! any help is appreciated :)
November 23, 2008 by z.

Chemistry
The combustion reaction for benzoic acid C6H5CO2H(s) + 15 2 O2(g) → 7 CO2(g) + 3 H2O(ℓ) has ∆H0 = −3226.7 kJ/mole. Use Hesss Law to calculate ∆H0 f for benzoic acid.
October 7, 2012 by Austin

chemistry
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 final value for the enthalpy of reaction you use for this intermediate reaction? C2H4 + 3 O2 2 CO2 + 2 H2O, H = -1410 kJ
November 24, 2014 by Anonymous

managerial accounting
Hess,Inc.Sells a single product with a contribution margin of $12 per unit, fixed costs of $74,400, and sales for the current year of $100,00. How much is Hess's Break even point?
July 10, 2007 by cathalina

bus 475
hess inc sells a single product with a contribution martgin of $12 per unit and fixed costs of $74400 and sales for the current year of $100000. how much is hess break even point?
January 18, 2010 by Anonymous

Accounting
Hess, Inc. sells a single product with a contribution margin of $12 per unit and fixed costs of $74,400 and sales for the current year of $100,000. How much is Hesss break even point?
June 13, 2010 by Anonymous

stats
Hess, Inc. sells a single product with a contribution margin of $12 per unit and fixed costs of $74,400 and sales for the current year of $100,000. How much is Hesss break even point?
July 7, 2010 by Ali

Chemistry
Using Hesss 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 2N2O(g) = 2N2(g)+ O2(g) Del(H)=-163.2kj Calculate Del(H) for the reaction: N2O(g) + NO2(g) = 3NO(g)
July 29, 2014 by Dan

Chemistry
Use Hess's law to calculate the enthalpy change for the reaction: 3C(s) + 3H2(g) C3H6(g) Given the following thermochemical equations: 2C3H6(g) + 9O2(g) 6CO2(g) + 6H2O(l) H = -4116.0 kJ/mol C(s) + O2(g) CO2(g) H = -393.51 kJ/mol H2(g) + O2(g) H2O(l) H = -...
March 16, 2012 by Hailee

Chemistry
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) delta H = -163.2kj. Using Hesss Law calculate delta H for the reaction: N2O(g) + NO2(g) = 3NO(g)
July 3, 2014 by Brett

Chemistry
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) delta H = -163.2kj. Using Hesss Law calculate delta H for the reaction: N2O(g) + NO2(g) = 3NO(g)
July 3, 2014 by Dan

Chemistry
The phrase the heat absorbed or released by a system undergoing a physical or chemical change at constant pressure is a. the change in enthalpy of the system. b. the change in internal energy of the system. c. the definition of a state function. d. the temperature change of ...
July 2, 2013 by Jessica

chemistry
Use Hess's law and the following equations to calculate H for the reaction N2(g) + 2O2(g) N2O4(g). 2NO2(g)->N2O4(g) H = 57.0 kJ/mol N2(g)+O2(g)->2NO(g) H = 180.6 kJ/mol 2NO2(g)->2NO(g)+O2(gH = 114.4 kJ/mol
May 14, 2012 by princess cunningham

Chem 121
Use Hess's law and the reactions 1) 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 (g) to determine the enthalpy for the reaction CH4 (g) + 2CH 2 (g)---> CH2 Cl 2 (g) + 2HCl (g)?
March 29, 2011 by Jessica Jones

Chemistry
When solving Hess law problems,do we need to use all the equations given to get the Htotal or just choose the relevant equations that are related to the final equation required? Let's say there r 5 equations given,but the relevant equations are 3 only ,so we can neglect the ...
March 23, 2012 by Meenaakshi

Chemistry
Find the enthalpy for : 4Fe + 3O2 = 2Fe2O3 I got the following informations: Fe + 3H2O = Fe(OH)3 + 3/2H2 - Enthalpy is 160.9 kj H2 + 1/2O2 = H2O - Enthalpy is -285.8 kj Fe2O3 + 3H2O = 2Fe(OH)3 - Enthalpy is 288.6 I try using Hess Law but cannot solve it. Can anyone help me ...
May 13, 2013 by Shadow

Chemistry
Why wouldn't you do this reaction directly in a lab (and would rather use Hess' Law to determine the enthalpy of formation)?: 1/2N2(g) + 2H2(g)+ 1/2Cl2(g) -> NH4Cl(s) I don't think the reactants are that dangerous...? It's still pretty safe to do in a lab, isn't it? Are ...
February 18, 2013 by a Canadian

Hess's law
I need some help with this one please... A+B ----> 2 D H= -765.3 kj S= 344 j/k C ------> D H= 521 kj S= -171 j/k calculate G at 298 K for A+B ------> 2C I know I need to use the formula G= H-TS but I dont know how to get the numbers.
March 20, 2013 by Caitlin

Chemistry
Mg + 2HCl -> MgCl2 +H2 delta H = ? MgO + 2HCl (aq) -> MgCl2+ H2O delta H = ? H2+ 1/2O2 -> H2O delta H = -285.8 kJ Using Hess' Law find both the missing delta H values.
March 28, 2012 by Hunter

Science, Chemistry
Hess's law ____. A) makes it possible to calculate ΔH for complicated chemical reactions B) states that when you reverse a chemical equation, the sign of ΔH does not change. C) determines the way a calorimeter works D) describes the vaporization of solids Highly ...
May 9, 2014 by Samantha Taylor Greenfield

Chemistry
In accordance with Hessfs Law, manipulate the following equations and their Hrxnfs to calculate Hrxn for the reaction HClO4 + NH3 NH4ClO4... HClO4(aq)+ LiOH(aq) LiClO4(aq)+H2O(l) CH3COOH(aq)+ NH3(aq) NH4CH3COO(aq) CH3COOH(aq)+LiOH(aq) LiCH3COO(aq)+H2O(l)
July 7, 2013 by Angela

chemistry
My chem book gives me the following Hess' Law example: Mg + 2HCl --> H2 MgCl2 Delta H1 MgO +2HCl --> H2O +MgCl2 Delta H2 H2 + 1/2 O2 --> H2O Delta H3=-68.3kcal The desired reaction is the formation reaction of MgO as follows: MgS +1/2 O2 --> MgO Delta H final= ...
December 6, 2012 by marcus

Science-Chemistry
1. What is Charless law? State the definition of the law in words. What are the assumptions of Charless law? Write mathematical equations that represent the law. What can you do with Charless law? Using a gas-filled balloon as an example, describe what happens to ...
May 31, 2013 by Help needed.... Danielle

Chemistry
Using data from the following reactions and applying Hess's law, calculate the heat change for the slow reaction of zinc with water (answer must be in kJ/mol Zn): Zn(s) + 2 H2O(l) ----> Zn^2+(aq) + 2 OH-(aq) + H2(g) (ΔHrxn = ?) H+(aq) + OH-(aq) ----> H2O(l) (Δ...
October 15, 2012 by Amanda

chemistry
Using data from the following reactions and applying Hess's law, calculate the heat change for the slow reaction of zinc with water (answer must be in kJ/mol Zn): Zn(s) + 2 H2O(l) ----> Zn^2+(aq) + 2 OH-(aq) + H2(g) (ΔHrxn = ?) H+(aq) + OH-(aq) ----> H2O(l) (Δ...
October 16, 2012 by stephon

Chemistry
Reposted: Use Hess's law to calculate the enthalpy change for the reaction: 3C(s) + 3H2(g) yield C3H6(g) Given the following thermochemical equations: 2C3H6(g) + 9O2(g) yield 6CO2(g) + 6H2O(l) enthalpy change= -4116.0 kJ/mol C(s) + O2(g) yield CO2(g) enthalpy change= -393.51 ...
March 17, 2012 by Hailee

Chemistry
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 able to write the reaction that relates to an ionization energy and that relates to an electron affinity. I broke it up into: Na(g)--> Na^(+)+e...
November 3, 2012 by Ezra

trigonometry
Use logarithms and the law of tangents to solve the triangle ABC, given that a=21.46 ft, b=46.28 ft, and C=3228'30" I have to use logarithms and law of tangents . and then provide the check. which says law of sine or mollweids equation. I can't us the cosine law. If you ...
February 26, 2011 by Anon

Levy
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 Hess's law to calculate the heat of the reaction MnO2(s) + H2(g) MnO(s) + H2O(l)
January 11, 2012 by Ari

CHEM
Can you please check my work? I got -4.3KJ/mol If this is not right can you tell me what I am doing wrong? Thank you! Questions. 1.a. Use Hess's Law and the measured mean enthalpy changes for the NaOH-HCl and NH3-HCl reactions to calculate the enthalpy change to be expected ...
November 8, 2013 by Lauren

Chemistry
In accordance with Hess's Law, manipulate the following equations and their change in Hrxn to calculate change in Hrxn's for the reaction HClO4 + NH3 N NH4ClO4... HClO4(aq)+ LiOH(aq) LiClO4(aq)+H2O(l) CH3COOH(aq)+ NH3(aq)  NH4CH3COO(aq) CH3COOH(aq...
July 7, 2013 by Angela

Chemistry
The molar heat of reaction, H rxn , for the reaction of Ca(s) + 2H+(aq)-> Ca2+(aq) + H2(g) was found to be -550kJ/mol The change Hrxn , for the reaction of CaO(s) + 2H+(aq)-> Ca2+(aq) + H2O(l) was found to be -189kJ/mol Based on these results if the formation of water is...
February 21, 2009 by Anonymous

chemistry
A studen is asket to calculate the amount of heat involved in changing 10.0 g of liquid bomine at room temperature (22.5 C) to vapor at 59.0 C. To do this, one must know specific heat (0.474 J/g*C), boiling point (59 C), and heat of vaporization (29.6 kJ/mol) of bromine.In ...
March 30, 2011 by Lena

HIPPA
please check my answer thanks If HIPPA law is stricter than state law, which standards should you follow and why ? What if state all was stricter ? This is all I have so far any input would be great HIPPA laws are stricter than any state law. This standard over rules any state...
May 12, 2008 by Casie

Bus law
Why is the United State a common law country? We're a common law country because we follow precedents established over hundreds of years in Britain and the U.S. Common law is followed except when statutory law opposes a specific practice. Check this site for more information...
February 19, 2007 by mike

Chemistry
Which of the following is the best definition of Hess' Law? A. Heat is always released by the decomposition of 1 mole of a compound into its constitute elements. B. The enthalpy of a process is the difference between the enthalpy of the products and the enthalpy of the ...
February 20, 2008 by Anonymous

chemistry
1. what gas law does the nitric oxide relate to and why? (**charles law, boyles law, combined gas or gay-lusaacs law) 2. What gas law does nitrogen monoxide relate to? (**charles law, boyles law, combined gas or gay-lusaacs law)
October 4, 2010 by navroz

Chemistry
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 to the formation reaction of MgO, you will need to include the following: H2(g) + 1/2O2(l) delta H =-241.8 kJ Using Hess's Law and manipulating...
February 14, 2012 by Hannah

Chemistry
Calculate the free energy (ΔG˚) of reaction (kJ) for the equation as written at 298 K (Dependence of temperature on enthalpy can be disregard). If the answer is negative, enter the sign and then the magnitude. Express your answer to three significant figures. CaO(s...
March 13, 2010 by Anonymous

Chemistry - General, Hess's Law
In an experiment, 11.6g of a salt was dissolved in 100.0ml of water contained in the above calorimeter, all at an initial tmperature of 24.5 degrees Celsius. After dissolution was complete, the temperatur was 31.8C. The specific heat of the solution is 3.63J/gxC and the ...
July 24, 2009 by Sahar

chem urgent!
Set up a Hess's law cycle, and use the following information to calculate Hf 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) H = -138.4 kJ 2 NO(g) + O2(g) 2 NO2(g) H = -114 kJ 4 NH3(...
November 6, 2012 by hannah

Chemistry (Hess's Law)
NO2(g) → 1⁄2N2(g) + O2(g) ΔH1 = -33.9 kJ NO2(g) → NO(g) + 1⁄2O2(g) ΔH2 = 56.5 kJ What is ΔH for the reaction 1⁄2N2(g) + 1⁄2O2(g) → NO(g) ?
April 15, 2011 by Monty

12 Chemistry
What is the molar enthalpy of combustion of magnesium? This was the lab question that I was asked to find after performing a lab based on Hess' law. I can't find anywhere in my notes how to calculate this, and the text book doesn't explain their steps properly, and I have ...
March 29, 2008 by Chase (sorry if this long)

World History Answer Check
1. Explain the signifigance of the Twelve Tables and the Law of Nations to the development of political thought? A: The significance of the Twelve Tables to the development of politcal thought was that they established the idea that all free citizens had a right to the ...
September 13, 2014 by Victoria

government
Which branch of the law regulates wrongful acts involving injury to ones person, property, or reputation in a situation not covered by the terms of a contract? A. common law B. tort law C. civil law D. contract law
March 8, 2012 by Johana

government
Which branch of the law regulates wrongful acts involving injury to one's person, property, or reputation in a situation not covered by the term of a contract? A. common law B. tort law C. civil law D. contract law
April 2, 2012 by Charlette

Chemistry
Calculate the enthalpy change of formation for the following reactions using Hess's law, and the enthalpies of formation given in Figure 4: b) MgO +2HCl --> MgCl2 +H2O c)NaOH+ HCl -->NaCl +H20 Figure4: the given enthalpies of formation compound values are: Mg(OH)2 is ...
January 30, 2014 by BOB

chemistry - decomposition of water(help)
Hydrogen is a very appealing fuel, in part because burning it produces only non-polluting water. One of the challenges that researchers face in making hydrogen fuel a reality is how to produce hydrogen economically. Researchers are investigating methods of producing hydrogen ...
March 3, 2011 by Farah

chemistry - decomposition of water(help)
Hydrogen is a very appealing fuel, in part because burning it produces only non-polluting water. One of the challenges that researchers face in making hydrogen fuel a reality is how to produce hydrogen economically. Researchers are investigating methods of producing hydrogen ...
March 3, 2011 by Farah

college chemistry-thermochemistry
i have one more question: I know this one has to do with hess's law but i'm not sure of how to get the enthalpy of vaporization from this? Clculate the enthalpy of vaporization of solid potassium bromide to a gas of ions, the process KBr--->K{+1}(g)+Br{-1}(g), from the ...
November 8, 2008 by maryanne

Chemistry
Ethylene glycol, HOCH2CH2OH, is used as antifreeze. It is produced from ethylene oxide, C2H4O, by the following reaction. C2H4O(g) + H2O(l) → HOCH2CH2OH(l) Use Hess's law to obtain the enthalpy change for this reaction from the following enthalpy changes. 2 C2H4O(g) + 5 ...
December 13, 2009 by Mariam

chemistry
Ethylene glycol, HOCH2CH2OH, is used as antifreeze. It is produced from ethylene oxide, C2H4O, by the following reaction. C2H4O(g) + H2O(l) → HOCH2CH2OH(l) Use Hess's law to obtain the enthalpy change for this reaction from the following enthalpy changes. 2 C2H4O(g) + 5 ...
October 29, 2010 by caroline

bus law
What is the chronological order of the major legislation that makes up the history of employment law in this country? For each law, state the social problem the law was designed to address, and discuss how employment law has affected the workplace in the last two decades.
September 2, 2010 by kash

Chemistry
Find the enthalpy of combustion of magnesium using Hess' law given the following data (assume that exactly 100.0 mL of HCl was used in each trial and that HCl is in excess) Magnesium/HCl reaction: Grams of Mg= 0.244g Initial temp= 32.2 degrees celsius Final temp= 21.3 degrees ...
July 21, 2014 by Liz

Chemistry
Which of the following is the best definition of Hess' Law? A. Heat evolved in a given process can be expressed as the sum of the heats of several processes that, when added, yield the process of interest. B. The enthalpy of a process is the difference between the enthalpy of ...
May 7, 2007 by Jared

chemistry
consider the following changes at constant temperature & pressure H2O(s) --yields-- H20(l); Delta H1 H2O(l) --yields-- H2O(g); Delta H2 H2O(g) --yields-- H2O(s); Delta H3 Using Hess's law, the sum of the deltas is a. equal to 0 b. sometimes greater than zero, sometimes less ...
November 14, 2012 by marcus

question about math (law of syllogism/detachment)
Does anyone know about the law of syllogism and law of detachment. If so, can you check my work.
September 13, 2009 by Candy

Chemistry
Which of the following is the best definition of Hess' Law? A. Since enthalpy is a state function, it will be different if a reaction takes place in one step or a series of steps. B. Heat is always released by the decomposition of 1 mole of a compound into its constitute ...
February 24, 2008 by Anonymous

Chemistry(Urgent, please check!!!)
The equation A + 2 B = C + D describes an elementary reaction, which takes place in a single step. Thus, the rate law must be? My answer is k(A)(B)^2 Is this correct?
February 29, 2012 by Hannah

Government Law question
What kind of law is it when judges make the law by their decisions on the bench? ___ Law
January 14, 2013 by Allyson

Chem
RXN #1: H2 (g) + O2 (g) --> H2O2 (l) ; delta-H =? Calculate the enthalpy change (delta-H1) for the reaction above (RXN #1) using the information below and Hess' Law. RXN A: H2O2 (l) --> H2O (l) + 1/2 O2 (g); delta-H=-98.0 kJ/mol RXN B: 2 H2 (g) + O2 --> 2 H2O (l); ...
July 12, 2011 by Ally

trigonometry (repost) Mathmate
I want to start by saying thank you . You have no idea how much u have helped me understand logarithms, even better then the books i have (it poorly explains the subject of trigonometry let alone logarithms and antilog). Your last explanation was very clear and i even ...
February 26, 2011 by Anon

Chemistry
The four statements below are used for applications of Hess's law. One of the statements is erroneous. Choose that statement. a) the value of delta H for any reaction that can be written in steps is the sum of the values of delta H for each of the individual steps. b) when an ...
January 20, 2012 by Hannah

World History Answer Check (Ms.Sue)
How did King Henry II's goal to become more powerful affect the development of law? A: Henry's goal to become more powerful affected the development of law as it ultimately expanded the power of royal courts. Since royal courts were now found throughout England, a body of ...
September 14, 2014 by Victoria

Law
Research and identify a labor law that is specific to your state. Share a brief summary of the law with us and discuss why you believe this law is or is not important to the employer-employee relationship.
November 29, 2013 by Mattiazz

chemisty
2. (a) Given the following equations and H0rxn at 250C H3BO3(aq) HBO2(aq) + H2O(l) ∆H0rxn = -0.02kJ H2B4 O7(s) + H2O(l) 4HBO2(aq) ∆H0rxn = -11.3kJ H2B4O7(s) 2B2O3(s) + H2O(l) ∆H0rxn = +17.5kJ (i) Calculate ∆H0rxn for the reaction 2H3BO3(aq) ...
August 5, 2011 by ceasar3

legal and ethical issues
select a current or proposed law that impacts the delivery of human services what reliable resources are availiable to learn about the implications of this law? What is the purpose or rationale of the law? How will the law effect da-t-day operations within human service ...
June 2, 2008 by Tiff

CHEMISTRY
Show how Boyle's law can be derived from the ideal gas law.
May 7, 2010 by ~anonymous

chemistry
Explain how the use of masses, while not a component of Boyle's law, is related to the law.
April 24, 2010 by chase

Health Law
please check my answer thanks :) Sue says that her claim is based on the fundamental law of nation what does that mean(what source is Sue relying on) I think Sue is relying on the constiution
November 14, 2007 by Anonymous

New AP Chem Question for Dr. Bob
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 changing 1 mol of silica, SiO2, that has been extracted from sand into the pure silicon that is needed to make computer chips. Use the following data: ...
January 23, 2007 by Belinda

Chemistry
Can someone plese check my answer...thank you! According to Raoult's law, as the mole fraction of dissolved nonvolatile solute in a given amount of solvent increases, the solution vapor pressure: VARIES AT RANDOM?
December 18, 2007 by anonymous

chemsitry
c. Use the enthalpy diagram provided above and apply Hesss Law to determine the standard enthalpy of formation for C12O36H20N12 (s) using the results from part (a) and the following values: The standard enthalpy of formation of gaseous carbon dioxide is -393.5 kJ/mol The ...
October 23, 2010 by Nora

Chemisrty
Determine which law is appropriate for solving the following problem. What volume will 1.56 liters of a gas at 27C and 745 mmHg of pressure occupy at 100C and 700 mmHg of pressure? Law used: Boyle's Law Charles' Law Combined Gas Law
October 19, 2011 by Angel

Chemistry - Rate Law
The following example is given in my textbook: If a chemical equation is: NO2 (g) + CO (g) -> NO (g) + CO2 (g) The rate law is: Rate = k[NO2]^2 Usually you put in the reactants in their own sets of brackets, so why isn't the reactant CO involved in the rate law? I get it ...
January 31, 2007 by Belinda

bioethics
what is law natural law eternal law human positive law what is conscience different kinds of conscience pls need an answer thanks
June 20, 2011 by joyce

Grammar and Composition
please check my answers: write the plurals of the following singlular words. 1. guess : guesses 2. tongue : tongues 3. attorney-at-law : attorneys-at-law 4. theory : theories 5. leaf : leaves 6. tomato : tomatoes 7. mouse : mice 8. beach : beaches 9. piano : pianos 10. monkey...
October 15, 2009 by y912f

Law
Hi there! I have totally got to find out how the Aussie Law is similar to the US law. Anyway I DO like know that like Oz follows England law mainly but that isn't what I need. Bushells of Thanks Minnie
April 25, 2008 by Minnie

business
what is the chronological order of the major legislation that makes up the history of employment law in this country? for each law, state the social problem the law was designed to address and whether the law has solved the problem.
April 27, 2011 by Sean

Chemistry
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 rxn = -393.5 kJ 2H2 (g) + O2(g) ---> 2H2O (l) change of heat rxn = -571.6 kJ 2C2H2 (g) +5O2(g) ----> 4CO2(g) +2H2O (l) change of heat rxn...
May 5, 2013 by Lauren

Government
Precedent,while not an absolute contraint on the courts,is needed to: A.maintain legal consistency over time,so the confusion and uncertainty about the law can be avoided. B.preserve the courts as a majoritarian. C.check the president in the area of public law. D.balance the ...
December 28, 2011 by Calvin

Chemistry (henry's law and IGL)
Can Henry's Law be used for gases that obey the Ideal Gas Law? What about gases that do not obey the ideal gas law? when can you use/Not use henry's law?
November 8, 2012 by Ania

Chemistry
The reaction X + Y --> products was studied using the method of initial rates. The initial rate of consumption of X was measured in three different experiments. What is the value of the rate constant, k? *concentrations are in mol/L and initial rates are in molL-1s-1 Exp 1...
February 23, 2011 by Jamie

Chem
Set up a Hesss 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∘ = -137.3 kJ 2NO(g)+O2(g)→2NO2...
June 17, 2014 by Meg

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