Saturday
April 19, 2014

Search: calculate the enthalpy change

Number of results: 41,231

College Chem
Calculate the enthalpy change for the reaction NO(g) + O(g) --> NO2(g) from the following data: NO(g) + O3(g) --> NO2(g) + O2(g) ; ∆H = -198.9 kJ O3(g) --> 1.5O2(g) ; ∆H = -142.3 kJ O2(g) --> 2O(g) ; ∆H = 495.0 kJ
Sunday, May 8, 2011 at 2:53pm by maggie

Chem
1) A 15.0 g sample of nickel metal is heated to 100.0 C and dropped into 55.0 g of water, initially at 23.0 C. Calculate the final temperature of the nickel and the water, if the specific heat capacity of nickel is 0.444 j / g x C. 2) In a coffee-cup calorimeter, 1.60 g of ...
Tuesday, November 11, 2008 at 10:51pm by Kim

Chemistry- HWK CHECK
1. A solution in which no more solid can be dissoved is referred to as ____. Answer: saturated 2.At constant pressure, heat can be referred to as (entropy, enthalpy, or free energy). Answer: enthalpy The measure of disorder or randomness of a system is(entropy, enthalpy, or ...
Monday, August 4, 2008 at 9:10pm by Blair

chemistry
is this right? A formation equation... it shows the change in enthalpy that comes from forming one mole of the compound in its standard state.
Tuesday, April 22, 2008 at 9:54pm by trista

chemistry
what two conditions must be met by a thermochemical equation so that its standard enthalpy change can be given the symbol delta Hf?
Tuesday, October 12, 2010 at 1:02am by Leslie

Chemistry
For a given sample of CH3OH, the enthalpy change during the reaction is 82.6 kJ. How many grams of methane gas are produced?
Monday, March 5, 2012 at 6:51pm by Dylan

Chemistry Urgent
Assuming that kerosene is C11H24, calculate the standard enthalpy change when 1 mole of kerosene burns completely in oxygen, using the data below: ΔH of formation of C11H24(l) = -327 kJ mol ΔH of formation of CO2(g)= -394 kJ mol ΔH of formation of H2O (l)= -286 ...
Sunday, March 9, 2014 at 10:17pm by Ava

Chemistry
Why is the enthalpy of the reactants greater than the enthalpy of the products in an exothermic reaction? If it has something to do with the reactants having weaker bonds, why do weaker bonds have higher energy/enthalpy? It doesn't really make sense to me that weaker bonds ...
Monday, February 18, 2013 at 5:47pm by a Canadian

sosial studies
When 1.0 L solution Ba (NO3) 2 2.0 M at 25oC is mixed with 1.0 L solution of 2.0 M Na2SO4 in a calorimeter, the reaction that occurs to produce solid barium sulfate and temperature of the mixture increased to 28.1 oC. Calculate the enthalpy change per mole for the reaction ...
Wednesday, November 20, 2013 at 2:53am by Norsiah

chemistry
Given the thermochemical equation SO2(g) + O2(g) ---> SO3 (g) DH = -99.1 kJ calculate the enthalpy change (DH) when 89.6 g of SO2 is converted to SO3. 1. 69.3 kJ 2. -111 kJ 3. -139 kJ 4. 139 kJ 5. -69.3 kJ i got -139 kj but im so unsure may some one confirm it for me?
Tuesday, November 24, 2009 at 8:42pm by paneet

AP Chemistry
Calculate the entropy change when 4.44g of H2 reacts with O2 according to the reaction 2H2(g) + O2(g)→2H2O(ℓ) at 298 K and 1 atm pressure. The stan- dard molar enthalpy of formation of H 2O(ℓ) at 298 K is −285.8 kJ/mol. The corresponding free energy of ...
Tuesday, October 29, 2013 at 6:40pm by Gabriella

chemistry
You know the enthalpy change per 3.80 grams. You want to know the change per 32 (1 mole) grams. 73.7 kJ x (32/3.80) = ??
Monday, April 19, 2010 at 9:04pm by DrBob222

Chemistry
The enthalpy of combustion of benzoic acid is 26.4 kJ/g. What is the enthalpy of combustion expressed in joules per kilogram?
Wednesday, January 18, 2012 at 2:24pm by Cynthia

Chemistry
How many grams of MgO are produced during an enthalpy change of -96.0 KJ if 2Mg(s) + O2(g) -> 2MgO(s) and delta H= -1204kj
Tuesday, August 13, 2013 at 7:15pm by Carolyn

chemistry
how do i express the enthalpy of reaction calculated in question above as a molar enthalpy of reaction per mole of carbon dioxide?
Tuesday, January 8, 2013 at 2:53pm by shyanne

Chemistry
Calculate the quantity of heat released when 0.520 mol of sulfur is burned in air. uising the enthalpy detalH= -296
Tuesday, March 23, 2010 at 2:15pm by Vee

chemistry
calculate the enthalpy of mixing for the solution of 10% platinum and 90% gold .express your answer in units of kg/mole
Tuesday, May 7, 2013 at 1:15am by himani.

AP Chem
I had to do an experiment to calculate the enthalpy of solution of Epsom salts. I'm stuck on how to calculate the amount of the reactant in moles. Here's some preliminary data: 37.58 g of Epsom salts in the solution Molar mass of solution: 246.48 g/mol I'm not sure what to do ...
Thursday, December 20, 2012 at 7:17pm by Arianna

Chemistry
The molar enthalpy of vaporization for water is 40.79 kJ/mol. Express this enthalpy of vaporization in joules per gram.
Tuesday, November 20, 2012 at 12:46am by Rebecca

Chemistry 152
For a certain reaction, the enthalpy change is -148.5 kJ, the entropy change is 256 J/K, and the free energy change is -250.1 kJ. At what temperature is the reaction occurring, in C? Choose one answer. a. 85 b. 102 c. 124 d. 158 e. 210 I keep using equation delta G=delta H-T(...
Saturday, July 3, 2010 at 11:09am by Car

chemistry
The molar enthalpy of vaporization for water is 40.79 kJ/mol. Express this enthalpy of vaporization in joules per gram. b. The molar enthalpy of fusion for water is 6.009 kJ/mol. Express this enthalpy of fusion in joules per gram.
Monday, November 26, 2012 at 1:36pm by maryam

economics
take a shot, what do you think? Hint: calculate the change in revenue from each 0.2 increase in advertising, subtract the marginal cost of producing that extra unit. (e.g., calculate the change in profit from each 0.2 increase in advertising). Keep increasing advertising until...
Friday, December 4, 2009 at 1:21am by economyst

Chemistry
Originally the enthalpy is negative then how does it become postive and I have followed the steps and I came up 47.36 J/g degrees C. Also I don't understand why enthalpy is q if you could please explain that, and thankyou so much.
Monday, November 12, 2012 at 10:07pm by Annie

Science
Consider the following reaction: 2Na + Cl2  2NaCl ΔH = -821.8 kJ (a) Is the reaction exothermic or endothermic? (b) Calculate the amount of heat transferred when 5.6 g of Na reacts at constant pressure. (c) How many grams of NaCl are produced during an enthalpy ...
Tuesday, August 3, 2010 at 11:17pm by Joseph

chemistry
Can someone help me with this question? what two conditions must be met by a thermochemical equation so that its standard enthalpy change can be given the symbol delta Hf?
Tuesday, October 12, 2010 at 9:43am by Leslie

Chemistry
H2 + F2--> 2HF deltaH = 518.0 kJ H2 ----> 2H deltaH = 436.8 kJ F2 ---> 2F deltaH = 158.2 kJ (a) calculate Delta H for H + F---> HF (b) what is the standard enthalpy change of formation of F2 Help please!!! i think this is easier than i'm making it. for (b) would i ...
Thursday, April 28, 2011 at 11:15am by jessica

chemistry
what is the molar change in enthalpy when 100 g of ice is heated from -18.2C to -7.2C?(C=37.4 J/K*mol)
Friday, April 2, 2010 at 2:04pm by any

chemistry
5gCH4/16gCH4= 0.3125moles CH4 (0.3125molesCH4)x(891kJ)=278kJ Enthalpy change = 278kJ
Sunday, October 31, 2010 at 10:13pm by Anonymous

chemistry
What is the change in enthalpy for an isothermal, isentropic compression of an ideal gas from 2 atm to 12 atm?
Wednesday, October 23, 2013 at 1:23am by Carl

engineering
What is the change in enthalpy for an isothermal, isentropic compression of an ideal gas from 2 atm to 12 atm?
Wednesday, October 23, 2013 at 1:23am by Carl

science
Calculate the Molar Enthalpy of Neutralization (Hn) in kJ/mol of the reaction between a monoprotic acid and a monoprotic base, given the following information: The temperature change equals 5.30C, 50.0 mL of 1.00 M concentration of Acid 50.0 mL of 1.00 M concentration of ...
Sunday, November 17, 2013 at 3:33pm by brittany sheats

Chem
A gas is compressed from 73.7 L to 1.9 L at 0.70 atmospheres? In addition a total of 4400 J of heat are gained from warmer surroundings. What is the change in internal energy in kJ? I have a general idea of how to do this, but I tried and got -2851.8, which isn't right. What ...
Friday, October 19, 2012 at 12:42pm by Anonymous

college physics
Calculate the potential which is energy per unit charge (voltage) .0131 meters from a wire of charge density s. (assuming voltage 0 at infinity) Then calculate the voltage .0271 meters away. change in potential energy of the particle in moving is the charge times the change in...
Wednesday, January 27, 2010 at 5:58pm by Damon

Chemistry
A coffee-cup calorimeter initially contains 125 g water at 24.2 degrees celsius. Potassium bromide (10.5 g), also at 24.2 degree celsius, is added to the water, and after the KBr dissolves, the final temperature is 21.1 degrees celsius. Calculate the enthalpy change for ...
Monday, February 13, 2012 at 4:25am by Elle

Chemistry
Calculate the entropy change when 2.42 g of H2 reacts with O2 according to the reaction 2 H2(g) + O2(g) → 2 H2O(ℓ) at 298 K and 1 atm pressure. The standard molar enthalpy of formation of H2O(ℓ) at 298 K is −285.8 kJ/mol. The corresponding free energy ...
Sunday, October 14, 2012 at 6:54pm by sam

Chemistry
Calculate the entropy change when 2.42 g of H2 reacts with O2 according to the reaction 2 H2(g) + O2(g) → 2 H2O(ℓ) at 298 K and 1 atm pressure. The standard molar enthalpy of formation of H2O(ℓ) at 298 K is −285.8 kJ/mol. The corresponding free energy ...
Sunday, October 14, 2012 at 8:03pm by Austin

chemistry
what is the molar enthalpy change when 147 g of water cools from 90.0 degrees C to 17.0 degrees C
Wednesday, October 10, 2012 at 9:43pm by sam smith

Lauren
Which of the following has a standard enthalpy of formation value of zero at 25 degrees C and 1.0 atm A. Fe(s) B. Fe2O3(s) C. FeSO4(s) D. FeSO4(aq) E. FeS3(s) and what is enthalpy or how do you find it
Friday, November 16, 2007 at 5:37pm by Chemistry

Chemistry
The following reaction has a standard enthalpy of reaction of -146.0 kJ/mol: Cu2O(s) + 1/2 O2(g) -> 2CuO(s) The standard enthalpy of formation of Cu2O(s) is -168.6 kJ/mol. What is the standard enthalpy of formation of CuO(s)?
Friday, March 11, 2011 at 4:59pm by James

Chemistry
Data: C(graphite) + O2(g) forms CO2 (ga) Delta H = -393.5kJ H2(g) + 1/2O2(g) forms H2O(l)Delta H = 285.8kJ. CH3OH(l) + 3/2O2(g)forms CO2(g) + 2H2O(l)Delta H = -726.4 Using data above, calculate the enthalpy change for the raction below C(graphite) + 2H2 +1/2 O2(g) forms CH3OH(l)
Wednesday, October 27, 2010 at 8:29am by lavonne

Chemistry
with a platinum catalyst, ammonia will burn in oxygen to gove nitric oxide NO. What is the enthalpy change for the following reaction? NO + 3/2 H2O -----> NH3 + 5/4 O2
Monday, October 29, 2007 at 11:42pm by Lauren

Chemistry
Someone said, "Calculate the total delta H of the reaction and subtract the total delta H of the product from it. If you get a positive value, it radiates heat which means it's exothermic. If it is negative, heat is needed to get a reaction so it is endothermic." ...shouldn't ...
Monday, February 11, 2013 at 7:10am by A Canadian

Chemistry
Someone said, "Calculate the total delta H of the reaction and subtract the total delta H of the product from it. If you get a positive value, it radiates heat which means it's exothermic. If it is negative, heat is needed to get a reaction so it is endothermic." ...shouldn't...
Monday, February 11, 2013 at 6:54pm by A Canadian

Chemistry
What is the enthalpy change (in kJ/mol) for the following process? Na+(g) + Br-(g) --> NaBr (s) Hint: use the Born-Haber cycle Note: the reference state for Br2 is Br2(l) not Br2(g) Data (in kJ/mol): enthalpy of sublimation of Na(s): 107 standard enthalpy of formation of ...
Tuesday, February 1, 2011 at 11:50pm by Crystal

Chemistry (DrBob222)
Hi, here's my (almost) 2-paged lab report introduction (hopefully you remember it from yesterday). I went to class today, and actually a lot of my other classmates' introductions were over 2 pages! Now I'm feeling kind of insecure about mine, and I'm not even sure if 2 pages ...
Tuesday, February 19, 2013 at 5:39pm by a Canadian

chemistry
The fermentation of sugar (C6H12O6) to form ethanol (C2H5OH) and carbon dioxide (CO2) occurs according to the following equation: C6H12O6(aq) 2 C2H5OH(aq) + 2 CO2(g) kJ molC1 Hf (C6H12O6(s)) is C1275 Hf (C2H5OH(l)) is C277 Hbond (C=O) 799 (a) Assuming the heat of ...
Wednesday, November 3, 2010 at 6:12am by mailyn

Chemistry
What is the enthalpy change (in kJ) for burning 49.0 g of methyl alcohol? I tried this question and got the wrong answer of 1047.74. A gas is compressed from 73.7 L to 1.9 L at 0.70 atmospheres? In addition a total of 4400 J of heat are gained from warmer surroundings. What is...
Friday, October 19, 2012 at 12:02am by Anonymous

Chemistry
The enthalpy of solution of CaCl2 is -82.88kJ. If the specific heat of the solution is 4.184J/g*C and the calorimeter constant can be neglected, what will be the final temperature after 5.36g of CaCl2 is dissolved in 100.0g of H2O at 25.0C? I assume the enthalpy given is kj/...
Sunday, May 20, 2007 at 2:35pm by Em

Chemistry
A calorimeter contains 22.0 mL of water at 14.0 C. When 2.50 g of X (a substance with a molar mass of 66.0 g/mol) is added, it dissolves via the reaction X(s)+H_2O(l)--------> X(aq) and the temperature of the solution increases to 25.5 C. Calculate the enthalpy change, ...
Monday, April 2, 2012 at 2:24pm by Amanda

science
the standard enthalpy of formation of ammonia is -46 kj/mol. if the enthalpy of formation of hydrogen molecule is -436 kj/mol and that of nitrogen molecule is -712 kj/mol find the average bond enthalpy of N-H bond in ammonia
Tuesday, April 1, 2014 at 7:41am by bonnhi

Chemistry-Thermochemistry (grade 12)
A 65.0 g sample of 0.600 M HI at 18.46 degrees celsius is added to 84.0 g of solution containing excess KOH, also at 18.46 degrees celsius. The final temperature is 21.96 degrees celsius. Calculate the enthalpy of H for the reaction. Assume the specific heat of the solution is...
Thursday, February 16, 2012 at 1:06am by Rose Bud

chemistry
CH3OH(g) ----> CO(g) + 2H2 (g) (delta H =+90.7k) A) is heat absorbed or released in the course of this reaction? b) calculate the amount of heat transferred when 45.0g of CH3OH(g)is decomposed by this reaction at constant pressure. c) for a given sample of CH3OH, the ...
Monday, October 17, 2011 at 12:32am by Anna

chemistry
calculate the enthalpy of formation, per mole, of sucrose, C12H2211O(s). C12H22O11(s) + 12O2(g) --> 12CO2(g) +11H2O(l) deltaH=-5.65*10^3 kJ
Wednesday, March 23, 2011 at 3:17pm by Stacy

chemistry
calculate the enthalpy of formation, per mole, of sucrose, C12H2211O(s). C12H22O11(s) + 12O2(g) --> 12CO2(g) +11H2O(l) deltaH=-5.65*10^3 kJ
Wednesday, March 23, 2011 at 3:17pm by Stacy

thermochem
The phase transition occurs where there is a discontinuity in the specific heat. At the transition temperature, it becomes what is known mathematically as a multiple of the delta function, with an infinite height but a finite integral ve. T. The Cp dT integral there is equal ...
Wednesday, January 30, 2008 at 12:34am by drwls

Chem
Ok, so I have DeltaHrxn=(X+90)-(143+90). How do you calculate the enthalpy of O2 (X above) when it is not given to you. Am I even doing that right?
Monday, November 19, 2007 at 7:29pm by Dan

Chemistry
Calculate the longest wavelength of light that can break a H-O bond. The bond enthalpy of formation is 463 kj/mol
Friday, April 8, 2011 at 10:15am by Angelina

chemistry
By using the bond enthalpies and bond energies in thermochemical equations to calculate the reaction enthalpy of; H + Br=2HBr
Sunday, July 10, 2011 at 3:29am by Gift

Chemistry
Calculate the enthalpy of combustion of acetylene(per mol acetylene)using bond enthalpies and energy diagram
Friday, August 5, 2011 at 2:15pm by Gift

Chemistry
Calculate the enthalpy of combustion of acetylene(per mol acetylene) using bond enthalpies and energy diagram
Friday, August 5, 2011 at 6:20pm by Gift

Chemistry
If 1 mol of ice melts at its melting point of 273 K, the entropy change for the ice is 22.0 J/K. If the ice melts in someones hand at 34C, what is the change in the entropy of the universe? Assume a final temperature for the water of 0C. The enthalpy of fusion for ice is 6....
Monday, July 30, 2012 at 1:50pm by Taylor

CHEMISTRY
If 1 mol of ice melts at its melting point of 273 K, the entropy change for the ice is 22.0 J/K. If the ice melts in someones hand at 34C, what is the change in the entropy of the universe? Assume a final temperature for the water of 0C. The enthalpy of fusion for ice is 6....
Wednesday, August 1, 2012 at 7:12pm by MONICA

Chemistry
If 1 mol of ice melts at its melting point of 273 K, the entropy change for the ice is 22.0 J/K. If the ice melts in someones hand at 34C, what is the change in the entropy of the universe? Assume a final temperature for the water of 0C. The enthalpy of fusion for ice is 6....
Monday, July 30, 2012 at 1:50pm by zak

CHEMISTRY LAB
If the molecular mass for a chemical is 45.99 g/mol and the enthalpy of formation is 34 kJ/mol, the heat change will be
Sunday, February 21, 2010 at 3:01pm by Mary

chemistry, please help
2NO2(g)--> 2NO(g) + O2(g) , H=+114.2kJ (Note: H, S, G all have a degree sign next to them) NO: H(enthalpy)=90.3kJ/mol, S(entropy)=210.7J/mol*K, G(gibbs energy)=86.6 O2: H(enthalpy)=0, S(entropy)=?, G(gibbs energy)=0 kJ/mol NO2: H(enthalpy)=33.2, S=239.9, G=51 For part a, I ...
Monday, February 4, 2008 at 12:12am by apoorva

APChemistry
Thank you!!! Do catalysts affect: A, B, C, AB, AC, BC, or ABC???: where: A)activation energy B) enthalpy change (I am assuming this is delta H) C) value of the equilibrium constant thank you!!!
Monday, May 10, 2010 at 10:40pm by GRATEFUL AP CHEMISTRY STUDENT

Math
Enthalpy diagram? What if I asked this: "Can someone tell me whether a price diagram has two axis?" That of course makes not sense, nor does your question. When you say diagram, you have to be much more specific. Enthalpy versus what...time?...temperature?...mass? Because all ...
Sunday, March 3, 2013 at 5:47am by bobpursley

CHEMISTRY
Post a New Question Current Questions Homework Help: Chemistry Posted by Anonymous on Thursday, November 14, 2013 at 8:45pm. CONTINUE>>>>>>>>>>> The enthalpy changes for two different hydrogenation reactions of C2H2 are: C2H2+H2---->C2H4 ...
Thursday, November 14, 2013 at 9:40pm by Anonymous

chemistry
The only way I know to do this is to calculate the buffer capacity of each, then compare them. The buffer capacity is the number of moles of a strong acid or a strong base that causes 1.00 L of the buffer to undergo a 1.00 unit change in pH. So you calculate the pH of the ...
Sunday, December 12, 2010 at 5:28pm by DrBob222

chemistry
Calculate the enthalpy of reaction for the following: N2 + 3H2 -> 2NH3 they are all gases. Is this reaction endothermic or exothermic?
Monday, November 7, 2011 at 5:28pm by Chioma

chemistry
when one gram of water solidifies to ice 333.33 j of heat is evolved. calculate enthalpy of fusion of ice?
Tuesday, July 30, 2013 at 2:21pm by gopal

chemistry
The standard enthalpy of formation for sulfur dioxide gas is -296.8 J. Calculate the amount of energy given off in kJ when 30.0 g of SO2 is fromed from its elements
Thursday, March 31, 2011 at 12:34pm by adam

chem- i reallyneed help
Consider the following equations. N2H4(l) + O2(g) N2(g) + 2 H2O(l) H = -622.2 kJ H2(g) + 1/2 O2(g) H2O(l) H = -258.5 kJ H2(g) + O2(g) H2O2(l) H = -187.8 kJ Use this information to calculate the enthalpy change for the reaction shown below. N2H4(l) + 2 H2O2(l) N2(g) + 4 H2O(...
Tuesday, November 6, 2012 at 10:30am by hannah

chemistry
The heat of vaporization of liquid water at 373 K is 40.7 kJ/mol. The value of the enthalpy change when 2.00 g of steam condenses at 373 K is?
Sunday, November 28, 2010 at 7:17pm by Anonymous

Chemistry- HWK CHECK
#5: is Positive. It's not A, B, or C. Your question may be worded differently. But the correct answer should be "positive" for change in enthalpy. I did the lab, and my calculation supports it!
Monday, August 4, 2008 at 9:10pm by Foxyfresh

Chemistry
4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g) If standard enthalpy change is -906.2 kJ, what quantity of heat is evolved or absorbed in the formation of 17.0 g of NH3?
Sunday, May 1, 2011 at 5:45pm by Kat

Physics
Calculate C, the capacitance Q = charge = C V R = resistance = 3*10^13 *.0012/(.1*.1) i =V/R change in Q = i t = (V/R)*1*60 fraction = change in Q / Q
Saturday, March 13, 2010 at 8:36pm by Damon

Chemistry
Part A Calculate the standard enthalpy change for the reaction 2A+B --->2C +2D Use the following data: Substance Delta H(kJ/mol) A -263 B -391 C +203 D -523 Express your answer in kilojoules. MY ANSWER FOR PART A: Delta H =277 kJ PART B----THIS ONE I NEED HELP ON Express ...
Thursday, June 16, 2011 at 12:59pm by tina

Chemistry
Part A Calculate the standard enthalpy change for the reaction 2A+B --->2C +2D Use the following data: Substance Delta H(kJ/mol) A -263 B -391 C +203 D -523 Express your answer in kilojoules. MY ANSWER FOR PART A: Delta H =277 kJ PART B----THIS ONE I NEED HELP ON Express ...
Thursday, June 16, 2011 at 1:00pm by tina

chem
I got through the first part easily, got -352.9kJ Having trouble with the second part "The meals-ready-to-eat (MREs) in the military can be heated on a flameless heater. The source of energy in the heater is shown below. Mg(s) + 2 H2O(l) Mg(OH)2(s) + H2(g) Calculate the ...
Saturday, November 20, 2010 at 11:17pm by Anonymous

chemistry
Calculate the enthalpy of fusion of naphthalene (C10H8) given that its melting point is 128 Celsius and its entropy of fusion is 47.7 J (k*mol) .
Monday, April 29, 2013 at 10:39pm by Chloe

college chem 2
The enthalpy of vaporization of liquid diethyl ether is 26.0kJ/mol at 35'C calculate the deltaS' for vapor to liquid
Monday, March 24, 2014 at 3:08am by shel

Chemistry
Is there a value for the enthalpy of vaporization of water at any temperature? Or does the value change with different temperatures? And if there is just one value, do you know what it is?
Sunday, January 4, 2009 at 11:05pm by Unsure

Chemistry
Is there a value for the enthalpy of vaporization of water at any temperature? Or does the value change with different temperatures? And if there is just one value, do you know what it is?
Sunday, January 4, 2009 at 11:06pm by Unsure

Chemistry
Is there a value for the enthalpy of vaporization of water at any temperature? Or does the value change with different temperatures? And if there is just one value, do you know what it is?
Sunday, January 4, 2009 at 11:06pm by Unsure

chemistry
The melting of 0.140 g of Br2 (which occurs at -7.2 C at 1 atm pressure) absorbs 9.43 J of heat. Compute the enthalpy change in 2.00 mol of Br2 when it freezes.
Thursday, September 1, 2011 at 9:04pm by rafay

chemistry
gaseous hydrogen and fluorine combine in the reaction above to form hydrogen fluoride with an enthalpy change of -540kJ. What is the value of the heat of formation of HF(g)
Sunday, February 17, 2013 at 6:14pm by Sarah

Chemistry
Define a system and state the significant the enthalpy change for the system. Explain your reasoning? A) natural gas burning in a furnace B) melted wax solidifying
Wednesday, September 11, 2013 at 6:03pm by Saarah

Chemistry
What is the enthalpy change if 25.0 g of methane are burned? 890kJ of heat released for every mole of methane that reacts. CH4 + 2O2 = CO2 + 2H2O
Tuesday, March 18, 2014 at 5:31pm by Tracy

CHEM LAB
Calculate the Molar Enthalpy of Neutralization in kJ/mol of the reaction between a monoprotic acid and a monoprotic base, given the following information: *Make sure you report your answer using the correct sign* The temperature change equals 9.80 degrees C, 50.0mL of 1.00 M ...
Wednesday, November 6, 2013 at 8:35am by BRANDIE

CHEM LAB
Calculate the Molar Enthalpy of Neutralization in kJ/mol of the reaction between a monoprotic acid and a monoprotic base, given the following information: *Make sure you report your answer using the correct sign* The temperature change equals 9.80 degrees C, 50.0mL of 1.00 M ...
Wednesday, November 6, 2013 at 8:59am by BRANDIE

Chemistry - enthalpy of combustion(help!!!)
i need help with the below question, i have tried answering it, but do not know where to go after the equations, please start me off on how to find the enthalpy of combustion of at least one.... Consider methane, CH4, and hydrogen, H2, as possible fuel sources. (a) Write the ...
Wednesday, June 8, 2011 at 10:12am by Farah

physics
calculate the change in KE. Calculate the change in PE The KE of the plane decreased, the PE of the plane decreased. So something absorbed energy, probably the atmosphere.
Wednesday, September 22, 2010 at 7:21pm by bobpursley

Chemistry
A calorimeter contains 21.0 mL of water at 14.0 degreesC. When 1.90 g of X (a substance with a molar mass of 70.0 g/mol) is added, it dissolves via the reaction X(s)+H_2O(l)reacts to make X(aq) and the temperature of the solution increases to 28.5degreesC. Calculate the ...
Friday, October 22, 2010 at 12:04pm by Ellen

please check my answer
Consider the following equations. N2H4(l) + O2(g) N2(g) + 2 H2O(l) H = -622.2 kJ H2(g) + 1/2 O2(g) H2O(l) H = -258.5 kJ H2(g) + O2(g) H2O2(l) H = -187.8 kJ Use this information to calculate the enthalpy change for the reaction shown below. N2H4(l) + 2 H2O2(l) N2(g) + 4 H2O(...
Tuesday, November 6, 2012 at 9:34pm by hannah

Chemistry Urgent
A calorimeter contains 32.0mL of water at 13.0∘C . When 2.30g of X (a substance with a molar mass of 82.0g/mol is added, it dissolves via the reaction X(s)+H2O(l)X(aq) and the temperature of the solution increases to 30.0∘C . Calculate the enthalpy change, H ...
Tuesday, March 11, 2014 at 10:35pm by Anna

Chemistry Help!!
C3H8 + 5O2 ==> 3CO2 + 4H2O I suppose you want the standard enthalpy change using delta Hf values. delta Hrxn = (n*DHfproducts)-(n*DHfreactants)
Wednesday, October 12, 2011 at 1:47pm by DrBob222

Chemistry
What is the change in enthalpy when 4.00 mol of sulfer trixoide decomposes to sulfer dioxide and oxygen gas? 2SO2 + O2 ---> 2SO3 delta H = 198kJ
Monday, June 24, 2013 at 5:03pm by Jessica

Biochemistry
You wish to measure the change in G'for the hydrolysis of ATP: ATP ---> ADP + Pi but the equilibrium for the hydrolysis lies so far toward products that analysis of the ATP concentration at equilibrium is neither practical nor accurate. However, you have the following data...
Saturday, September 12, 2009 at 7:56pm by Mallory

Chemistry
What is the different b/n internal energy(^E) and enthalpy(^H)? Under what circumstances are internal energy and enthalpy nearly equal?
Wednesday, January 11, 2012 at 7:42am by Ethio

Pages: <<Prev | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>

Search
Members