Wednesday
May 22, 2013

# Search: calculate the quantity of heat, in kJ, required to raise the temperature of a 2.15kg iron ba 24 degrees Celsius

Number of results: 30,854

Chemistry
Some properties of aluminum are summarized in the following list. normal melting point 658°C heat of fusion 0.395 kJ/g normal boiling point 2467°C heat of vaporization 10.52 kJ/g specific heat of the solid 0.902 J/g°C (a) Calculate the quantity of energy required ...
Saturday, May 1, 2010 at 6:46pm by Charles

chemistry
Some properties of aluminum are summarized in the following list. normal melting point 658°C heat of fusion 0.395 kJ/g normal boiling point 2467°C heat of vaporization 10.52 kJ/g specific heat of the solid 0.902 J/g°C (a) Calculate the quantity of energy required ...
Saturday, May 1, 2010 at 5:54pm by Jake

chemistry
Calculate the energy in the form of heat, in kJ, required to convert 225 grams of liquid water at 21.0 °C to steam at 115 °C. Heat of fusion = 0.333 kJ/g; heat of vaporization = 2.26 kJ/g; specific heat capacities: liquid water = 4.18 J/g·°C., steam = 1.92 J...
Sunday, October 2, 2011 at 2:55am by Ninaya

Chemistry
22.) The molar heats of fusion and vaporization for water are 6.02 kJ/mol and 40.6 kJ/mol, respectively, and the specific heat capacity of liquid water is 4.18 J/gC. (1) What quantity of heat is required to melt 25.0 g of ice at 0C? (2) What quantity of heat is required to ...
Tuesday, March 5, 2013 at 8:33pm by Adriana

Chemistry Help!!!
1) When hydrazine (N2H4) is burned in a 253-g brick container, the temperature of the brick increases by 5.13 degrees Celsius. Calculate the quantity of heat released in this raection. The specific heat of brick is 0.840 J/(gC). 2) A sample of coal is burned in a bomb ...
Sunday, November 14, 2010 at 1:30pm by Sarah

Chemistry
1) When hydrazine (N2H4) is burned in a 253-g brick container, the temperature of the brick increases by 5.13 degrees Celsius. Calculate the quantity of heat released in this raection. The specific heat of brick is 0.840 J/(gC). 2) A sample of coal is burned in a bomb ...
Sunday, November 14, 2010 at 5:03pm by Sarah

Chemistry
1) When hydrazine (N2H4) is burned in a 253-g brick container, the temperature of the brick increases by 5.13 degrees Celsius. Calculate the quantity of heat released in this raection. The specific heat of brick is 0.840 J/(gC). 2) A sample of coal is burned in a bomb ...
Sunday, November 14, 2010 at 4:46pm by Sarah

Chemistry Help!!!
1) When hydrazine (N2H4) is burned in a 253-g brick container, the temperature of the brick increases by 5.13 degrees Celsius. Calculate the quantity of heat released in this raection. The specific heat of brick is 0.840 J/(gC). 2) A sample of coal is burned in a bomb ...
Sunday, November 14, 2010 at 1:30pm by Sarah

CHEMISTRY
Given that the specific heat capacities of ice and steam are 2.06 J/g°C and 2.03 J/g°C, the molar heats of fusion and vaporization for water are 6.02 kJ/mol and 40.6 kJ/mol, respectively, and the specific heat capacity of water is 4.18 J/g°C, calculate the total ...
Tuesday, November 2, 2010 at 11:41pm by Riley

chemistry
Given that the specific heat capacities of ice and steam are 2.06 J/g°C and 2.03 J/g°C, the molar heats of fusion and vaporization for water are 6.02 kJ/mol and 40.6 kJ/mol, respectively, and the specific heat capacity of water is 4.18 J/g°C, calculate the total ...
Tuesday, February 16, 2010 at 7:21pm by Emily

Chem
What is the quantity of heat evolved when 111.9 grams of H2O(l) is formed from the combustion of H2(g) and O2(g)? H2(g) + 1/2 O2(g) --&gt; H2O(l) Delta Ho = -285.8 kJ A. -0.4 kJ B. 1776.7 kJ C. 0.4 kJ D. -1776.7 kJ E. -6.2 kJ
Sunday, October 26, 2008 at 9:44pm by Kyle

Chemistry
2Fe2O3 -&gt; 4Fe+3O2 changeHrxn= +824.2 KJ The decomposition of 57.0 g of Fe2O3 results in The release of 23500 KJ of heat The absorption of 147 KJ of heat The absorption of 23500 KJ of heat The absorption of 294 KJ of heat The release of 294 KJ of heat The release of 147 ...
Tuesday, October 9, 2012 at 11:16pm by Anonymous

ap chemistry
the heat of neutralization for a strong acid in dilute water solution is about 60 kJ/mol of H+. What quantity of heat in kJ is produced when 100 mL of 3 M HCl is mixed with 100 mL of 1 M KOH?
Friday, September 24, 2010 at 9:26pm by Sarah

chemistry
q to heat water from 23.24 to 29.77 = mass H2O x specific heat H2O x delta T = xx J. Change to kJ. q2 to heat calorimeter = 6.35 x delta T = yy kJ. Add xx kJ + yy kJ to obtain total heat produced by 7.02 g sucrose. That gives you zz kJ/7.02 g. Convert to kJ/g and to kJ/mol. ...
Sunday, April 20, 2008 at 11:46am by DrBob222

chemistry
A gas absorbs 45 kJ of heat and does 29 kJ of work. Calculate the change in energy. The answer is 16 kJ, but I don't understand why. If a gas absorbs heat and does 29 kJ of work. Wouldn't they both be positive? Change in energy = q + w 45 kJ + 29 kJ = 74 kJ Why is the ...
Wednesday, March 31, 2010 at 10:59pm by Jake

chem
A quantity of 16.13 mL of a KOH solution is needed to neutralize 0.4883 g of KHP. What is the concentration (in molarity) of the KOH solution? I don't even know where to begin with the first one. Calculate the amount of heat liberated (in kJ) from 375 g of mercury when it ...
Thursday, February 26, 2009 at 11:50pm by ash

chemistry
Given that the heat of fusion of water is -6.02 kJ/mol, that the heat capacity of H2O(l) is 75.2 kJ/mol*K and that the heat capacity of H2O(s) is 37.7 kJ/mol*K, calculate the heat of fusion of water at -11 K.
Wednesday, January 27, 2010 at 3:44pm by im lost

college chemistry
Given that the heat of fusion of water is -6.02 kJ/mol, that the heat capacity of H2O(l) is 75.2 kJ/mol*K and that the heat capacity of H2O(s) is 37.7 kJ/mol*K, calculate the heat of fusion of water at -11 K.
Sunday, January 24, 2010 at 6:22pm by i'm stuck

ap chemistry
Propane (C3H8) is burned in oxygen to pro- duce carbon dioxide and water. The heat of combustion of propane is -2012 kJ/mole. How much heat is given off when 3.0 mol C3H8 are reacted with 10.0 mol O2? 1. 4024 kJ 2. 2012 kJ 3. 916 kJ 4. 1555 kJ 5. 5122 kJ 6. 672 kJ 7. 6036 kJ 8...
Wednesday, October 31, 2012 at 5:52pm by cheri

physics
heat to melt ice 2100 kj liquid 4186 kj steam 2010 kj heat to heat steam 301.5 kj
Thursday, April 21, 2011 at 12:39am by DMITRIC

Chemistry
How much heat is needed to melt a 25 gram ice-cube at 0 °C? The molar heat of fusion for water is 6.01 kJ/mol. A) 6.01 kJ B) 8.35 kJ C) 150.25 kJ D) 3.34 kJ E) 9.22 kJ
Friday, March 12, 2010 at 6:58pm by Natalie

Chemistry
Not quite. 6.01 kJ/mol x 3.50 mol = ?? Note that your arrangement gives kJ/mol; my arrangement the mol cancel to give kJ as the answer and that is the quantity of heat.
Sunday, May 16, 2010 at 6:13pm by DrBob222

Chemistry
You take 2 liters of water at 20 degrees Celsius and remove heat at 200W from it for 5 min. What is the temperature and state of the water after the experiment? Some properties of water: Heat of fusion: 333.55 kJ/kg, Heat of vaporization: 2257 kJ/kg, Heat capacity of steam: 2....
Monday, December 6, 2010 at 2:13am by Eddie

chemistry
this is my class data list of total heat (KJ) vs Mass of biodiesel fuel burned: Heat of combustion: 24948 J 606.48 J 35933.3 J 26763 J 24062.5 J 29400 J 6972 J Mass: 0.39 g 0.31 g 0.18 g o.43 g o.36 g o.28 g 0.34 g Heat absorbed: 9.729 KJ 1.9564 KJ 11.51 KJ 6.468 KJ 11.6 KJ 8....
Tuesday, March 18, 2008 at 8:40pm by Jonathan T

ap chemisty
Calculate the heat of formation of butane given that the heat of formation of H20(l) is -285.3 kj/mol and the heat of formation of CO2(g) is -393.5 kj/mol.
Friday, September 24, 2010 at 5:30pm by Sarah

chemistry
A 0.1375-g sample of magnesium is burned in a constant volume calorimeter tha has a heat capacity of 3024 J/C. the temperature increases by 1.126 C. calculate the heat given off by the burning Mg in kJ/g and kJ/mol
Friday, October 21, 2011 at 10:25pm by TROUBLED

Chemistry
Calculate the amount of heat (in kJ) required to convert 87.5 g of water to steam at 100°C. (The molar heat of vaporizaion of water is 40.79 kJ/mol.)
Wednesday, December 1, 2010 at 2:32pm by MC

Chemistry
Calculate the enthalpy change when 100. g of ice at 0.0 °C is heated to liquid water at 50.0°C. (The heat of fusion for water is 333 J/g.) 1)54.2 kJ 2)33.3 kJ 3)54,220 kJ 4)20.9 kJ
Tuesday, October 23, 2007 at 9:39pm by Robert

Science
Calculate the quantity of energy required to change 3.00 mol of liquid water to steam at 100°C. The molar heat of vaporization of water is 40.6 kj/mol
Monday, March 25, 2013 at 9:32pm by Emily

Chemistry
When a 8.00 g of KBr is dissolved in water in a calorimeter that has a total heat capacity of 4.6 kJ·K^-1 the temperature decrases by 0.290 K. Calculate the molar heat of solution of KBr in kJ/mol. DeltaH soln = ?
Wednesday, February 8, 2012 at 9:17pm by Eric

Molar heat of combustion question!
Calculate the molar heat of combustion of paraffin, expressed in units of kJ/mol. First calculate the thermal energy released when one mole of parafin burns) because one mole of parafin (c25h52) has a mass of 325g, the molar heat of combustion will be 352 times greater than ...
Tuesday, February 5, 2013 at 4:55pm by Allyson

Chem ? Help!
What is the answer and how do I Calculate the quantity of energy required to change 3.00 mol of liquid water to steam at 100°C. The molar heat of vaporization of water is 40.6 kJ/mol.
Monday, May 19, 2008 at 2:02pm by Lisa

Chemistry (Thermo)
Your answer to (a) looks correct. For (b), divided the heat release by the heat of fusion of water, 333 Kj per kg. For (c), divide the heat realse by (333 +418 kJ) = 551 kJ/kg For (c) add the heat of vaporization to the amount of heat required per kg, and divde that into the ...
Friday, September 10, 2010 at 10:25am by drwls

chemistry
Calculate the heat of formation of SiO4(s), given that the heats of formation of SiO2(s), -910.90 KJ/mol; H2O(l), -285.8 KJ/mol; HF (g), -271.1 KJ/mol. I know the heat of formation is products minus reactants but how do i do this when no reaction is given please help
Saturday, November 8, 2008 at 9:14am by matt

Chemistry
A quantity of ice at 0.0 degrees C was added to 33.6 of water at 21.0 degree C to give water at 0.0 degrees C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol and the specific heat is 4.18 J/(g * degrees C) q = mass x specific heat x delta T? q = mass x heat...
Monday, February 4, 2008 at 4:42pm by Lauren

Math/Physics
A quantity of water at 87 degrees C is cooled at a rate of 2844 MJ/h. After 40 minutes, the water has changed to ice, having a temperature of 243K. Calculate the mass of the water/ice. I know 243K = -30 degrees C I'm assuming I have to use my sensible and latent heat ...
Saturday, March 23, 2013 at 1:02am by Dylan

Chemistry
Lithium metal is a highly reactive metal that oxidizes instantly in water or air. Given the data below, calculate the energy required to heat 10.0 g of Li from 150.0 °C to 200.0 °C. Molar heat capacity (solid) = 3.58 J/°C • mol Molar heat capacity (liquid) = 4...
Thursday, April 25, 2013 at 11:53pm by Johnny

AP Chem
Consider the reaction 2 Al2O3(s) -&gt; 4 Al(s) + 3 O2(g) . H = +3339.6 kJ/mol What is the change in heat when 0.455 L of a 3.60 M Al solution reacts with excess O2 ? 1. -685 kJ 2. -21,962 kJ 3. -1368 kJ 4. -2738 kJ 5. -5477 kJ 6. -26,521 kJ 7. -424 kJ 8. -1695 kJ
Sunday, November 7, 2010 at 2:52pm by Beth

chemistry
The heat for the equation you wrote is 286 kJ/mol of product formed (which I found in a table) and since there are two moles of product, then 286 x 2 = 572 kJ for the reaction as written (to include the 2 moles). So as written the heat emitted is 572 kJ. Why the key wants to ...
Monday, May 18, 2009 at 5:06pm by DrBob222

chemistry 106
A 0.1589 g sample of solid magnesium is burned in a bomb calorimeter that has a heat capacity of 1769 J/°C. The calorimeter contains exactly 251 g of water, and the temperature increases by 1.126°C. Calculate the heat given off by the burning Mg, in kJ/g and in kJ/mol.
Wednesday, March 3, 2010 at 6:33pm by Tanisha

Math
A heat exchanger is used to warm apple cider using steam as the heat source. The cider is heated from an initial temperature of 4°C to a final temperature of 65°C. The steam enters the heat exchanger as 50% quality steam and exits as water condensate at 85°C. ...
Sunday, February 17, 2013 at 11:19am by Paul

chemistry
484 kJ heat released from 4 g hydrogen. 44.0 kJ heat used to vaporize the water/mole or 88 kJ heat used to vaporize 4 g hydrogen. 484-88 = 396 kJ net heat released. So We need 484 x (x grams/4) = 7.46 g hydrogen burned to produce the 396 kJ. Solve for x THEN CHECK IT TO MAKE ...
Sunday, October 31, 2010 at 5:16pm by DrBob222

chemistry - heat absorption (help)
moles ethanol = 0.1/46 = ?? heat absorbed = ?? x 38.58 = z kJ moles H2O = 0.9/18 = xx heat absorbed = xx x 44 = y kJ Total heat absorbed = 2.284 kJ according to my calculation but you need to confirm that.
Friday, April 1, 2011 at 8:34am by DrBob222

Chemistry (Thermo)
Your answer to (a) looks correct. For (b), divided the heat release by the heat of fusion of water, 333 Kj per kg. For (c), divide the heat realse by (333 +418 kJ) = 551 kJ/kg Note:I believe drwls make a typo here. I think he meant to type 751 and not 551. :-) For (c) add the ...
Friday, September 10, 2010 at 10:25am by DrBob222

Chemistry
The value of H° for the reaction below is -482 kJ. Calculate the heat (kJ) released to the surroundings when 12.0 g of CO (g) reacts completely.
Tuesday, April 6, 2010 at 8:16pm by Camarra

CHEMISTRY> HELP QUICK! pls
A system loses 14.2 kJ of heat while performing 7.2kJ of work on the surroundings. If the initial internal energy, E, is 77.6 kJ, what is the final value of E? 56.2 kJ 70.6 kJ 99.0 kJ 84.6 kJ
Friday, August 20, 2010 at 9:44pm by Lucinda

Chemistry
q = heat generated = mass water x specific heat water x delta T. Convert to kJ. Then kJ/8 = kJ/gram. Then convert that to kJ/mol. Post your work if you get stuck.
Wednesday, February 10, 2010 at 3:52am by DrBob222

ap chem
The heat of combustion of propane is -2,220.1 kJ/mol calculate the heat of formation, delta Hf, of propane given that delta Hf of H20= -285.3 kJ/mol and delta Hf of CO2 = -393.5 kJ/mol
Tuesday, March 15, 2011 at 12:09am by Anonymous

Physics
The heat of fusion of 334 J/g (or kJ/kg) is a measured quantity. Usually that value is used to determine the heat needed to melt ice; e.g., q = heat required to melt 25 g ice = 25 g x 334 J/g = ?? J.
Tuesday, June 30, 2009 at 3:31pm by DrBob222

chemistry
heat needed is mass air x sp. h. air x delta T. You have the MOLAR specific heat of air so you need to change the volume to grams to mols. Calculate q. CH4 + 2O2 ==&gt; CO2 + 2H2O + 50.1 kJ/kg heat generated. Knowing q (in J/g) and the reaction produces 50.1 kJ/kg, ...
Wednesday, November 12, 2008 at 8:04pm by DrBob222

physics
If we apply 300 kJ of heat to 2500 moles of air at constant pressure, what is the change in internal energy? Answer a. 214 kJ. b. 100 kJ. c. 180 kJ. d. 75 kJ.
Friday, October 15, 2010 at 5:48pm by jim

Chemistry
Calculate the total quantity of heat required to convert 25.0 g of liquid CCl4(l) from 25.0°C to gaseous CCl4 at 76.8°C (the normal boiling point for CCl4)? The specific heat of CCl4(l) is its heat of fusion is and its heat of vaporization is
Tuesday, April 13, 2010 at 7:32pm by Bob

chemistry
q = mass H2O x specific heat H2O x (Tfinal-Tinitial) q = heat loss by the water in J. Divide by 1000 to convert to kJ. That gives you total kJ. Then kJ/3.90 gives kJ/gram NH4NO3 and (kJ/3.90)*molar mass NH4NO3 gives kJ/mol.
Wednesday, July 4, 2012 at 3:32pm by DrBob222

Science
Many portable gas heaters and grills use propane, C3H8(g), as a fuel. Using standard enthalpies of formation, calculate the quantity of heat produced when 11.90 g of propane is completely combusted in air under standard conditions. I got -600 kj but its wrong
Wednesday, November 7, 2012 at 4:39pm by Samantha

chemistry
Calculate the heat of formation of SiO4(s), given that the heats of formation of SiO2(s), -910.90 KJ/mol; H2O(l), -285.8 KJ/mol; HF (g), -271.1 KJ/mol.
Friday, November 7, 2008 at 6:15pm by matt

Chem!!
The value of ƒ¢H‹ for the reaction below is -482 kJ. Calculate the heat (kJ) released to the surroundings when 12.0 g of CO(g) reacts completely. 2CO(g) + O2(g) ¨ 2CO2(g)
Wednesday, June 6, 2012 at 2:39pm by Harlem

chemistry
The enthalpy of vaporization at 298 K for diethylether (C4H10C) is 26.0 kj/mol. How much heat would be required to vaporize 1.00 L of the ether at 298 K if its density is 0.714 g/L ? A) 250 kj B) 74.1 kj C) 186 kj D) 130 kj E) 440 kj
Monday, June 21, 2010 at 2:28pm by Jim

chemistry
How much energy do you need to heat the water? That is q = mass x specific heat x (Tfinal-Tinitial) = 1000 x 4.184 x (100-33) = approximately 310 kJ. CH4 + 2O2 ==&gt; CO2 + 2H2O + 49.3 kJ/gram 1 g x 310 kJ/49.3 kJ = grams
Saturday, February 4, 2012 at 9:12pm by DrBob222

chemistry
What is the lattice energy of NaBr? heat of formation of NaBr = -362 kJ/mol heat of sublimation for Na = 107.30 kJ/mol ionization energy for Na = 496 kJ/mol bond dissociation energy for Br2 = 190 kJ/mol electron affinity of Br = -325 kJ/mol heat of vaporization for Br2 = 30.90...
Saturday, December 4, 2010 at 8:57pm by chemistry

chemistry 106
Methanol, ethanol, and n-propanol are three common alcohols. When 1.00 g of each of these alcohols is burned in air, heat is liberated. Calculate the heats of combustion of these alcohols in kJ/mol. (a) methanol (CH3OH), -22.6 kJ (b) ethanol (C2H5OH), -29.7 kJ (c) n-propanol (...
Wednesday, March 3, 2010 at 6:34pm by Tanisha

science
Calculate the heat of combustion of candle wax in kJ/mole. The standard heat of formation (&#8710;Hf ) of candle wax (C20H42) is -2230 kJ/mole. The standard heat of formation (&#8710;Hf ) of carbon dioxide is -394 kJ/mole. The standard heat of formation (&#8710;Hf...
Thursday, April 25, 2013 at 8:02pm by emma

Chemistry - Thermodynamics
Calculate the heat energy release: The number of moles of CH4 you are burning is 67.2/16 = 4.20 mol Multiply that by 885.4 kJ/mol for the heat release. Then divide that by 87.5 kJ/K for the temperature rise. Or, you could do it all at once Delta T = (67.2g*885.4kJ/mol)/(16 g/...
Wednesday, December 12, 2007 at 2:53am by drwls

chemistry
The dH for the reaction below is -482 kJ. Calculate the heat (kJ) released to the surroundings when 12.0 g of CO (g) reacts completely. 2CO(g) + O2(g) --&gt; 2CO2(g)
Monday, April 16, 2012 at 11:11am by tank

chemistry
The dH for the reaction below is -482 kJ. Calculate the heat (kJ) released to the surroundings when 12.0 g of CO (g) reacts completely. 2CO(g) + O2(g) --&gt; 2CO2(g)
Monday, April 16, 2012 at 11:11am by tank

ap chemistry
How much heat is released if 2.00 moles CF2Cl2 reacts with 70.0 g F2 with a 75.0 percent yield? CF2Cl2 + F2 ! CF4 + Cl2 H for this reaction is -401 kJ/mol rxn. 1. 553 kJ 2. 739 kJ 3. 985 kJ 4. 601 kJ 5. 1069 kJ 6. 802 kJ
Wednesday, October 31, 2012 at 6:04pm by cheri

ap chemistry!! help!!
some solutes have large heats of solution, and care should be taken in preparing solutions of these substances. The heat evolved when sodium hydroxide dissolves is 44.5 KJ/mol. What is the final temperature of the water, originally at 20.0 degrees Celcius. used to prepare 500....
Tuesday, January 9, 2007 at 3:44pm by john

chem 101
How much heat is required to raise the temperature of exactly one liter of water fro m 60 °F to 180 °F? a. 79 kJ b. 120 kJ c. 251 kJ d. 279 kJ correct** e. 502 kJ help with solution?
Friday, April 13, 2012 at 2:35pm by Anonymous

Chemistry
CO + 2H2 ---&gt; CH3OH Change in heat= -90.7 KJ/mol Calculate the mass of hydrogen formed when the change in heat is +90.7 KJ/mol 2 moles of H2= 1 mole of CH3OH 2(1x2)g 2(2)g =4g Am I correct?
Saturday, October 24, 2009 at 5:25pm by Anonymous

chemistry
Given the thermochemical equation 2SO2(g) + O2(g) &#8594; 2SO3(g), &#916;H= -198 kJ/mol, how much heat is evolved when 600. g of SO2 is burned? A. 5.46 x 10-2 kJ B. 928 kJ C. 1.85 x 103 kJ D. 59,400 kJ E. 3.71 x 103 kJ
Tuesday, October 9, 2012 at 5:21pm by Anonymous

Chemistry
The heat capacity of liquid water is 4.18 J/g•&#61616;C and the heat of vaporization is 40.7 kJ/mol. How many kilojoules of heat must be provided to convert 1.00 g of liquid water at 67&#61616;C into 1.00 g of steam at 100&#61616;C? A. 22.7 kJ B. 40.8 kJ C. 2....
Thursday, February 3, 2011 at 8:01am by Dorian

chemistry
The value of delata h for the reaction below is -186 kJ. Calculate the heat Kj released from the reaction of 25g of Cl2
Friday, January 27, 2012 at 4:05am by ashely

I dont understand. in the formula Q=C*M*deltaT, do you use 4.200 kj/mol as C. Is the answer to question one, calculate the heat involved in the trial, 1.19 KJ?
Sunday, January 1, 2012 at 11:08pm by tessa

Physicis
melting point of copper = 1083.0 °C heat capacity of copper = .39 kJ/kg-K heat of fusion of copper = 207 kJ/kg so to warm it up Qin = .39 kJ/kgK(1083-83)K(3kg) = 1170 kJ then to melt it Qin = 207kJ/kg (3 kg) = 621 kJ total Qin = 1791 kJ or 179,100 J
Monday, December 10, 2012 at 10:11am by Damon

science
A heat exchanger is used to warm apple cider using steam as the heat source. The cider is heated from an initial temperature of 4 degrees celcius to a final temperature of 65 degree celcius. The steam enters the heat exchanger as 50% quality steam and exits as water condensate...
Monday, March 4, 2013 at 8:02pm by Bev

Yes, you calculate kJ/mol when you do this. If you want kJ per half mole, then multiply by 1/2 and that gives you kJ for whatever problem you are solving. However, it will ALWAYS be kJ/something; i.e., kJ/mol, kJ/g, kJ/500 mg or what have you. If you want to type in your ...
Tuesday, November 11, 2008 at 5:16pm by DrBob222

Chemistry II
The total volume of hydrogen gas needed to fill the Hidenbrug was 2.0e8 L at 1.0 atm and 25 degrees Celsius. How much heat was evolved when the Hidenburg exploded, assuming all the hydrogen reacted? I will be happy to critique your thinking on this. First, calculate the moles ...
Sunday, May 20, 2007 at 8:01pm by Jayd

Food Chemestry
A heat exchanger is used to warm apple cider using steam as the heat source. The cider is heated from an initial temperature of 4 degrees celcius to a final temperature of 65 degree celcius. The steam enters the heat exchanger as 50% quality steam and exits as water condensate...
Monday, March 4, 2013 at 7:27pm by Bev

Chemistry II
I will be happy to critique your thinking on this. First, calculate the moles of H2 used. 2.0e8 L H2/22.4 L H2 = 8.9e6 mol H2 For every 2 mol H2 used -572 kJ of energy is produced -572 kJ/2 mol H2 = -2.86e2 kJ/mol I have a balanced equation with this problem. It is: 2 H2 + O2...
Sunday, May 20, 2007 at 9:33pm by Jayd

Chemistry
Calculate the heat released when 64.5g of steam at 119 C is converted to water at 36 C. Assume the specific heat is 4.184 J/g*C for water, the specific heat of steam is 1.99J/g*C, and the heat of vaporization is 40.79 kJ/mol for water.
Friday, June 17, 2011 at 6:59pm by Sydney

Chem
The value of ƒ¢H‹ for the reaction below is -482 kJ. Calculate the heat (kJ) released to the surroundings when 12.0 g of CO(g) reacts completely. 2CO(g) + O2(g) ¨ 2CO2(g) *I just want to how to solve this problem as in an equation, not the answer...
Friday, June 8, 2012 at 3:03pm by Harlem

Chemistry - please this is urgent
To a calorimeter containing 41.80g of water at 29.95oC, 11.7999 of a salt was added with stirring. As the salt dissolved, the temperature rapidly changed to 37.85oC before slowly returning to room temperature. 1. Calculate the Heat of Solution. Given that the Heat of Formation...
Friday, March 14, 2008 at 1:36am by girl who needs help in chemistry right now

Chemistry
A quantity of ice at 0.0 degrees C was added to 33.6 of water at 21.0 degree C to give water at 0.0 degrees C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol and the specific heat is 4.18 J/(g * degrees C) q = mass x specific heat x delta T? q = mass x heat...
Monday, February 4, 2008 at 12:52pm by Lauren

Chemistry
A quantity of ice at 0.0°C was added to 25.0 g of water at 21.0°C to give water at 0.0°C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol and the specific heat is 4.18 J/(g · °C). _g
Saturday, January 28, 2012 at 12:10pm by jessica

chem
Am I missing something? First, what's the question? Is it to calculate the heat released by the reaction? Or is it something else? 56.2 kJ/mol x 0.120 mol = 6.744 kJ which rounds to 6.74 kJ to three significant figures (s.f.). I OFTEN find that when students are keying ...
Sunday, February 28, 2010 at 11:36pm by DrBob222

Chemistry
Calculate the heat (in kJ) required to transform 58.60 g of dinitrogen tetraoxide from a solid at a temperature of -9.3 °C to a gas at 47 °C. Report your answer to one decimal place. Data: Molar mass of dinitrogen tetraoxide, N2O4 = 92.011 g/mol Melting point = -9.3 &...
Monday, December 5, 2011 at 1:29pm by Matthew

chemistry
You need to know the delta H for the reaction. That isn't listed in the problem but you can look it up. How much heat do you need? That's q = mass H2O x specific heat H2O x (Tfinal-Tintial) You have the data to calculate q needed. Then 24.3 g Mg x (q in kJ/delta H iin ...
Tuesday, May 14, 2013 at 3:49pm by DrBob222

Chemistry
Ethanol (C2H5OH) has been produced since antiquity by the fermentation of fruits and vegetables. Given the following data, if 5.87 kJ of energy are transferred to 13.3 g of frozen ethanol at -130.0 °C, what is the final temperature of the sample? Heat capacity (solid) = 0....
Thursday, April 25, 2013 at 11:52pm by Johnny

chemistry
Using a coffee-cup calorimeter, it is found that when an ice cube with a mass of 24.6 g melts, 8.19 kJ of heat are absorbed. (a) Calculate the change in enthalpy per gram and per mole of water. (b) Write the thermochemical equation for this physical change. (c) What mass of ...
Tuesday, November 1, 2011 at 6:32pm by john

Chemistry
drwls, if you are there, I got an answer of 42.5 Kelvin, so then that means it is a negative number if converted to degrees Celsius? Question: The heat capacity of a bomb calorimeter is 87.5 kJ/K (this value is for the total heat capacity including that of the water jacket ...
Wednesday, December 12, 2007 at 8:26pm by Anne

Science
Chemistry Enthalpy Calculations? Given the equation: CaO + H2O ----&gt; Ca(OH)2 A 1 g sample of CaO is dissolved in 100 ml water with density 1.00g/ml. The temperature rise is 3.7 degrees C. The specific heat is 4.00 J/g*deg. 1. Calculate the heat (in J) absorbed/given off...
Thursday, October 18, 2012 at 5:46pm by Pablo

Chemistry
Given the thermochemical equation: 2ZnS(s) + 3O2(g) „³ 2ZnO(s) + 2SO2(g) £GH = --879 kJ Calculate the heat evolved (in kJ) when 560 grams of ZnS is converted to ZnO. Please explain throughly with answers.
Tuesday, June 15, 2010 at 6:11pm by Shayla

Chemistry
The first one is q = mass H2O x specific heat H2O x (Tfinal-Tinitial) The water is what absorbed the heat generated by the reaction. Your value of 5.6 kJ is the heat generated by 0.31 g or by (0.31/24.3) moles Mg. The usual reporting is done in kJ/mol; therefore, 5.6 kJ x (24....
Sunday, March 27, 2011 at 11:45pm by DrBob222

Heat of Formation
When 10.00 g of iron is burned in O2(g)to form Fe3O4 (s) , enough heat is generated to raise the temperature of 784 g of water from 18.0 C to 38.0 C. Calculate the heat of formation of Fe3O4 (s) under these conditions in kJ/mol.
Friday, November 6, 2009 at 2:13pm by Kyle

chemistry
CH3OH &#61664; CO + 2H2 &#61508;H = +90.7kJ 9. For the forward reaction, is heat being absorbed or released? 10. How much heat would be transferred if 45.0 g of CH3OH is decomposed? 11. What quantity of CH3OH decomposition would lead to an enthalpy change of 18.5 kJ
Wednesday, May 11, 2011 at 10:01pm by Anonymous

chemistry
CH3OH &#61664; CO + 2H2 &#61508;H = +90.7kJ 9. For the forward reaction, is heat being absorbed or released? 10. How much heat would be transferred if 45.0 g of CH3OH is decomposed? 11. What quantity of CH3OH decomposition would lead to an enthalpy change of 18.5 kJ
Wednesday, May 11, 2011 at 10:00pm by Anonymous

Chemistry 2 ap
Yes. I wondered if confuded was a new word I should learn. I think the problem is a stoichiometry problem IF you know the heat of combustion. Do you know that? If so, then C3H8 + 5O2 ==&gt; 3CO2 + 4H2O So it takes 44 g C3H8 to generate ??kJ (the heat of combustion ...
Thursday, October 28, 2010 at 2:48pm by DrBob222

Chemistry II
C4H4 (g) + 2 H2 (g) --&gt; C4H8 (g) Combustion reactions involve reacting a substance with oxygen. When compounds containing carbon and hydrogen are combusted, carbon dioxide and water are the products. Using the enthalpies of combustion for C4H4 (-2341 kJ/mol), C4H8 (-...
Sunday, May 20, 2007 at 6:52pm by Jayd

chemistry
If you need only the heat required to vaporize it, then most of the data provided is not useful (heat fusion, etc). First, convert 3.50 L to grams using the density listed. I looked up the heat of vap on the web and found 32.54 kJ/mol. Change that to J/gram 32.54 kJ/mol x (1 ...
Monday, December 8, 2008 at 3:14pm by DrBob222

Chemistry
Calculate the heat change (q) in kJ for each reaction. Assume the density of the acid solutions is 1.00 g/mL and the heat capacity is 4.184 J/g*°C. i have the Ti and Tf..what equation do i use?
Wednesday, May 25, 2011 at 1:27pm by ChemGeek

Chemistry
Heat obtained from CH4 = 891 kJ x 143/16 = ? kJ. ?kJ = mass H2O x specific heat H2O x (Tfinal-Tinitial) Solve for mass H2O and convert to kg.
Monday, January 30, 2012 at 8:35pm by DrBob222

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