April 25, 2014

Search: Thermochemistry

Number of results: 53

Chemistry-Thermochemistry (grade 12)
Thermochemistry determine the final temperature if 45.67 kJ of heat energy is removed from 18.5 g of H2O (g) at 122 degrees Celsius useful information sp. heat H2O (s) = 2.03 J/g(degree C) sp heat H2O (l) = 4.18 J/g(degree C) Sp heat H2O (g) = 2.01 J/g(degree C) enthalpy H Fus...
Wednesday, February 15, 2012 at 11:12pm by Rose Bud

How do you find [delta]Hvap?
Wednesday, March 19, 2008 at 10:21pm by James

Calculate the amount of heat liberated (in kJ) from 374 g of mercury when it cools from 83.7C to 19.1C.
Sunday, October 5, 2008 at 12:56pm by james

3CO(g)+ Fe2O3(s) --> 2Fe(s) + 3CO2(g) + 24.7 kJ. How much heat is released when 56 grams of CO react?
Tuesday, December 14, 2010 at 11:22pm by Hannah

When 1 mol of a gas burns at constant pressure, it produces 2426 J of heat and does 6 kJ of work. What is Delta H, q, and w?
Monday, October 18, 2010 at 7:44pm by Michelle

what is the formula to find the mass of propane that must be combusted to produce 188.3kj of energy?
Saturday, August 11, 2012 at 10:30am by Anonymous

thermochemistry college
does anyone know profesor of green river community college, auburn,wa, sue critchlow ????
Tuesday, December 8, 2009 at 8:42pm by eva

It takes 45.0 J to raise the temperature of an 9.70 g piece of unknown metal from 13.0 degrees C to 24.5 degreesC. What is the specific heat for the metal?
Sunday, October 17, 2010 at 9:20pm by Michelle

If 18 g of Kr initially at 0.5 bar and 18 L is brought to 0.49 bar and 5L, what is the overall change in enthalpy of this process? Assume that Kr is an ideal gas.
Friday, December 2, 2011 at 2:22pm by LaurenB

How many grams of water at 0 degrees C can be frozen into ice at 0 degrees C if 55.0 kJ of heat is removed? delta Hsolid= -6.01 kJ/mol
Tuesday, December 14, 2010 at 11:23pm by Hannah

The heat ofvaporization of water at 373K is40.7kj/mol. Find q for the evaporation of 491g of water at this temperation
Friday, April 13, 2012 at 12:11am by Anonymous

I have a test on the general concepts of thermochemistry tomorrow. how should i study for it since its not based on problem solving, just concepts?
Wednesday, October 24, 2007 at 12:40pm by Nick

I need to perform a chemical demonstration on thermochemistry or kinetics or colligative properties for chemistry class. However I cannot have demonstrations involving fire.
Tuesday, January 12, 2010 at 8:14am by alex

Compute the amount of heat released (absolute value) when 2.3 kg of liquid ethanol is burned in excess oxygen to make carbon dioxide and liquid water.
Saturday, December 3, 2011 at 2:43pm by LaurenB

A student mixes 85.7 g of water at 68.0C with 50.7 g of water at 24.5C in an insulated flask. What is the final temperature of the combined water
Sunday, October 5, 2008 at 12:55pm by james

A total of 2.00 mol of a compound is allowed to react in a foam coffee cup that contains 167 g of water. The reaction caused the temperature of the water to rise from 21.0 to 24.7 degrees C. What is the enthalpy?
Sunday, October 17, 2010 at 9:50pm by Michelle

The standard enthalpy of formation of n-octane is -249.95 kJ/mol. Compute the amount of heat liberated when 5.24 g of n-octane is burned completely with excess oxygen to form carbon dioxide and liquid water.
Sunday, December 4, 2011 at 8:58pm by LaurenB

When 19 mL of water at 22 C is combined with 18 mL of water at 64 C, what is the final temperature of the water?. The specific heat of water is 4.184 J/g/K and its density is 1.0 g/mL.
Friday, December 2, 2011 at 2:21pm by LaurenB

The enthalpy formation of ethanol, C2H5OH, is -277.0 kJ/mol @ 298.15 K. Calculate the enthalpy of combustion of one mole of ethanol, assuming that the products are CO2(g) & H2O (l).
Monday, April 18, 2011 at 5:16pm by Morgan

If a chalice made of pure gold weighing 1.24 kg and initially at 15 C is filled with 100.0 mL of water at 89 C, what is the final equilibrium temperature of the system? The heat capacities of water and gold are 75.29 and 25.42 J/mol/K, respectively.
Friday, December 2, 2011 at 2:26pm by LaurenB

college chemistry-thermochemistry
A 1.50g sample of NH4NO3(s) is added to 35.0g of water in a foam cup and stirred intil it dissolves. The temperature of the solution drops from 22.7 to 19.4 degrees celcius. What is the heat of dissolution of NH4NO3, expressed in kJ/mol NH4NO3?
Saturday, November 8, 2008 at 8:49pm by maryanne

A chemical reaction takes place in a container of cross-sectional area 100 cm2 . As a result of the reaction, a piston is pushed out through 19 cm against an external pressure of 596 torr. What is the value for w for this reaction?
Sunday, October 14, 2012 at 3:42pm by valerie

A 1.00-g sample of solid calcium was burned in fluorine to give a 1.95 g sample of pure CaF2. The energy given off in this reaction was 30.3 kJ. Given this information, we can say that the heat of formation of 1 mol of CaF2 is
Saturday, June 19, 2010 at 12:43am by joan

A sample of liquid mercury (mass 58 g and temperature 149.0 C) is poured into 79 g of H2O at 19 C. Calculate the final temperature of the mixture, assuming no heat is lost. The heat capacities of Hg and H2O are 27.98 and 75.33 J/mol/K, respectively.
Friday, December 2, 2011 at 2:26pm by LaurenB

I'm confused about the difference between the q in q=mc(Tf-Ti) and (Delta)H, or enthalpy. What exactly does enthalpy mean and how is that different than q? (I'm also confused about what Gibbs Free Energy actually means; I know that if it's negative, the reaction is spontaneous...
Tuesday, December 2, 2008 at 11:55pm by Kevin

A constant pressure calorimeter having a heat capacity of 60.8 kJ/K is used to measure the energy released from burning a compound in excess oxygen to form CO2(g) and H2O(l). If the enthalpy of combustion of the compound is -2914.0 kJ/mol and the temperature of the calorimeter...
Sunday, December 4, 2011 at 8:57pm by LaurenB

chemistry-Thermochemistry (grade 12)
calculate enthalpy of H for the reaction N2H4(l) + 2H2O(l) -> N2(g) + 4H2)(l) Given the reactions N2H4(l) + O2(g) -> N2(g) + 2H2O(l) Enthalpy of H = -6.22.2 kJ H2(g) + (1/2)O2(g) -> H2O(l) enthalpy of H = -285.8 kJ/mol H2(g) + O2(g) -> H2O2(l) enthalpy of H = -187....
Thursday, February 16, 2012 at 1:14am by Rose Bud

chemistry-Thermochemistry (grade 12)
calculate enthalpy of H for the reaction N2H4(l) + 2H2O(l) -> N2(g) + 4H2)(l) Given the reactions N2H4(l) + O2(g) -> N2(g) + 2H2O(l) Enthalpy of H = -6.22.2 kJ H2(g) + (1/2)O2(g) -> H2O(l) enthalpy of H = -285.8 kJ/mol H2(g) + O2(g) -> H2O2(l) enthalpy of H = -187....
Thursday, February 16, 2012 at 1:36pm by Rose Bud

Thermochemistry, calorimetry
The density of ice is 0.9168 g/cm3. The density of water is 0.9998 g/cm3. Calculate the difference between ΔU (internal energy) and ΔH (enthalpy) during the fusion of 2.5 moles of ice at atmospheric pressure.
Tuesday, November 20, 2012 at 6:38pm by Peter

When 1.477 mole of an inorganic salt were dissolved in 1.00 L of water in a constant pressure solution calorimeter, the temperature of the calorimeter changed from 25.00oC to 24.40 oC. The total heat capacity of the calorimeter including all its contents was 2.18 kJ oC-1 What ...
Friday, June 12, 2009 at 12:25am by Douglas

Compute the change in temperature when 1.1 g of sodium chloride is dissolved in 200.0 mL of water initially at 28 C. The heat capacity of water is 4.184 J/mL/K. Neglect the heat capacity of the NaCl. Species ΔfH (kJ/mol) NaCl(aq)-407.3 NaCl(s) -411.2
Friday, December 2, 2011 at 4:02pm by LaurenB

Chem. Copper and Chromium. Random Q...
So, I have a general chemistry test. My teacher said to know... "Copper and Chromium exceptions." I have no idea what that means. I am currently learning about Thermochemistry and the Quantum Theory of an Atom. Do you have any idea what this might mean?? Thank you for any ...
Saturday, November 15, 2008 at 1:13am by Sarah

Suppose 23.6 g of ClF3(g) and 40 g of Li(s) are mixed and allowed to react at atmospheric pressure and 25 C until one of the reactants is used up, producing LiCl(s) and LiF(s). Using the NIST value for the enthalpy of formation of ClF3 (, calculate the ...
Saturday, December 3, 2011 at 2:44pm by LaurenB

Thermochemistry Ap Chem homework
Any help would be great, even if it is just a way to start or a formula. Calculate the heat necessary to convert 10.0 g of water (just melted) at 0 degrees Celcius to water at 20 degrees Celcius, assuming that the specific heat remains constant at 1 cal/gram degrees celcius.
Monday, November 15, 2010 at 5:58pm by Chris

Calculate the final temperature of solution when 10 g of oxalic acid, (COOH)2(s), is dissolved in 110.0 mL of water that is initially at 26 C. The enthalpies of formation of oxalic acid in the solid and aqueous phases are -826.8 and -818.8 kJ/mol, respectively. The heat ...
Friday, December 2, 2011 at 2:25pm by LaurenB

In a thermochemistry experiment the reaction of 0.0857 g of an unknown metal and an excess of 4.0 M HCl resulted in a 0.210 mL decrease in the volume of an ice/water mixture. Calculate the enthalpy of this reaction per 1 g of metal reacted. Needed data: density of water at 273...
Saturday, December 1, 2007 at 4:25pm by Raj

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 (Thermochemistry)
Is there any equation out there that links the change in enthalpy (H) to the change in cell potential/voltage (E)? Yes, but the relationship involves the Gibbs Free Energy, which is G = H - TS, snd S is the entropy change. The change in G is approximatly the change in H in ...
Thursday, August 2, 2007 at 8:39am by Vic

please help! Is RTP in chemistry (thermochemistry and electrochemistry) referring to room temperature of 25degreeC (or 298K) and 1atm, or 20degreeC (293K) and 1atm? In my lecture notes on gas law, they stated RTP refers to 25degreeC, but in my electrochem lecture notes they ...
Sunday, November 6, 2011 at 4:57am by Hailey

I need help on finding the definitions to these: Pressure being constant, the amount of heat in a chemical equation ___________. Randomness of particle measurement is called __________. Calories required to convert 1gm of liquid to vapor without a change in temperature ...
Tuesday, April 6, 2010 at 9:41pm by Bill

topic: thermochemistry i'm not really sure how to go about his question. i'm not sure with formula to use. (perhaps Cspht= q/(m x deltaT)?)can you please help me step by step or give me a hint and i'll post my answer, pretty please? "250g of hot coffee at 95 degree celsius are...
Saturday, April 16, 2011 at 7:00pm by marie

Suppose a 0.17-kg billiard ball is rolling down a pool table with an initial speed of 4.5 m/s. As it travels, it loses some of its energy as heat. The ball slows down to 3.5 m/s and then collides straight-on with a second billiard ball of equal mass. The first billiard ball ...
Friday, October 30, 2009 at 4:54pm by Kyle

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 ...
Saturday, November 8, 2008 at 10:38pm by maryanne

thermochemistry chem conceptual. i just want to check my understanding of this Say you got this: 1)A + b=c A=4.0 grams and -91.8kj evolve How do you find change of H ? I guess you convert A to grams and then shove it under the evolved heat ? ie. change of H= -91.8kj/2 mol= 2)...
Friday, August 7, 2009 at 1:23am by Jim_R

In lab we did thermochemistry, where we are supposed to find the heats of solution, heat change of calorimeter and molar heat solution of the salt. I calculated that the calorimeter constant for the water we had was 883.194 Joules. We took 1/10 of a mole of NH4Cl and tried to ...
Sunday, October 31, 2010 at 3:44pm by Rani

Path A A sample of gas in a cylinder of volume 3.96 L at 327 K and 3.28 atm expands to 7.34 L by two different pathways. Path A is an isothermal, reversible expansion. Calculate the work for Path A. Answer in units of J. Path B Path B has two steps. In the first step, the gas ...
Tuesday, October 5, 2010 at 8:10pm by Nick

I would really appreciate some help with this thermochemistry problem! I'm really confused as to why I keep getting the wrong answers... I have gotten w=-1.305kj and energy change = 78.13kj... both of which were marked wrong. Here's the question: The oxidation of copper(I) ...
Sunday, November 3, 2013 at 1:38pm by DC

what is the mass of a lead block that if heated to 100.0 dgrs C and placed in a container with 50.0g of ice at 0.00dgrs C produces a final water sample of 15.0dgrs C? Sh of Pb= 0.128J/g dgrsC step by step solution and answer q1 for Pb block = mass x sp.h. x (Tf - Ti). mass Pb...
Wednesday, April 11, 2007 at 9:48pm by crystine cole

Thermochemistry please
I really need help on this problem... ===================== Hydrocarbon Formula Delta H (kj/mol) 1,3-Butadiene C4H6(g) 111.9 a) calculate the fuel value in kJ/g for this compound and determine the percentage of hydrogen by mass. I've tried it for hours yet I can't figure out ...
Tuesday, January 9, 2007 at 4:15pm by Jina

An ice hotel that is made of 410 metric tons of ice and 12200 metric tons of snow is being melted. The company is going to siphon the melted water into nearby streams. The company is using large industrial sized acethylene to do the job. Your job is to order the rigth amount ...
Tuesday, February 21, 2012 at 4:28pm by JAMES

Find the false statement(s) about the thermochemistry experiment in which nitric acid is reacted with sodium hydroxide, and the enthalpy of the reaction is measured using an ice calorimeter. i. Regardless of which strong acid and strong base are used for the neutralization ...
Sunday, November 16, 2008 at 3:48am by Anonymous

My question is more conceptual. It is expressed in a series of two problems: What energy change occurs when 1.2 moles of methane combust with an enthalpppy change of -434 KJ? CH4+2O2 TO CO2+2H20 I understand it is simply the moles of mthane times the enthalpy change yet I am ...
Tuesday, March 19, 2013 at 10:44pm by Sean

what is the enthalpy change in kilojoules for the combustion of 1 mol of ethanol, C2H5OH (l), to form gaseous carbon dioxide and gaseous water? use bond energies to calculate your answer. (hint: there is a double bond in carbon dioxide and oxygen) the answer is supposed to be...
Tuesday, January 23, 2007 at 3:17pm by Sienna

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