Search: thermo

Number of results: 56

sci/275
A. apple http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html No.
Tuesday, December 9, 2008 at 10:26pm by Ms. Sue

science
Sorry, I didn't post the site. http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/sweat.html
Thursday, October 23, 2008 at 11:44pm by DrBob222

Science
Using the second lay of thermodynamics, way energy cannot be recycled? Some energy is lost to entropy increase, and entropy is unusable energy. http://hypertextbook.com/physics/thermal/thermo-second/
Friday, July 6, 2007 at 9:49pm by Anonymous

chemistry
Look up the Dulong-Petit law. http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/dulong.html
Monday, October 18, 2010 at 7:17pm by DrBob222

Chemistry
http://antoine.frostburg.edu/chem/senese/101/thermo/faq/enthalpy-from-bond-energies.shtml
Sunday, January 22, 2012 at 10:53pm by DrBob222

chemisttry
I searched google.com and found a number of esoteric and highly theoretical discussions about thermodynamics. I know you want basic stuff; I found this one which seems to start from scratch and it appears they keep the math to a minimum. Here it is for you to read. This ...
Thursday, June 7, 2012 at 3:33pm by DrBob222

thermo
You need to read and correct your post. It makes no sense as it stands.
Wednesday, October 3, 2012 at 6:43am by DrBob222

Chem Question (thermo)
DG = -47940 + RT*ln[1/(0.023*0.13)]
Thursday, March 1, 2012 at 6:21pm by DrBob222

thermo
Please see your next post, whic I saw first. Sra
Friday, November 5, 2010 at 1:42am by SraJMcGin

physics - another thermo problem
thanks. i guess the dimensions in the beginning was supposed to throw me off
Thursday, September 18, 2008 at 5:40pm by Nik

Design and Technology
Why is the acrylic memory process only possible with thermo plastics?
Saturday, September 13, 2008 at 4:51am by Lilly

Physical science
Thank you for using the Jiskha Homework Help Forum. Although this is not my area, some of these sites may help you: 1. http://en.wikipedia.org/wiki/Heat 2. http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heat.html
Thursday, October 18, 2007 at 4:00pm by SraJMcGin

Chemistry
How can you predict whether the change in entropy for a system will be positive or negative? Like if the enthalpy is negative what will the entropy be? Try these 2 sites: http://www.shodor.org/unchem/advanced/thermo/index.html http://en.wikipedia.org/wiki/Chemical_reaction
Saturday, May 19, 2007 at 3:50pm by Christian

Chemistry
It is balanced; however, some profs are not impressed with fractional numbers (but thermo profs always allow them).
Wednesday, September 29, 2010 at 12:24am by DrBob222

physics, thermo
calculate the heat required to produce 1.7 kg of wet steam at 2000 kpa from water at 160 degrees celsius and a dryness fraction of 81%, answer in kj.
Monday, May 27, 2013 at 2:35pm by chad, please help

Thermo Dynamics
Air loses heat to the surroundings at a rate of Q.= t/6 where out Q. is in Watts and t is time in seconds. For 20 minutes of operation, determine the heat loss from the air in kWhr???
Tuesday, May 10, 2011 at 3:13pm by Justin

cooking
I haven't tried any of these -- but I suggest you experiment with some of them. http://sci-toys.com/scitoys/scitoys/thermo/ice_cream/ice_cream.html http://www.google.com/search?source=ig&hl=en&rlz=1G1GGLQ_ENUS333&q=homemade+ice+cream&aq=f&oq=
Friday, June 19, 2009 at 9:58pm by Ms. Sue

Thermo
Calculate the standard cahnge in enthalpy for the combusation of coal/ Show the balnaced reaction. How does one get the balanced reaction of coal? Coal has many substances that make up its compsistion
Sunday, March 18, 2012 at 8:04am by Scott

Thermo
Heat input is not necessarily zero in an isothermal process. An example would be heating a gas and letting it expand enough to keep the temperature the same. This is one of the steps of a Carnot cycle engine. Another example would be melting ice!
Friday, March 12, 2010 at 2:18pm by drwls

physics
http://en.wikipedia.org/wiki/Refraction http://en.wikipedia.org/wiki/Snell's_law http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/phase.html
Sunday, January 13, 2013 at 3:36pm by Elena

thermo
Consider a cylinder containing air at 1200 kPa and 350 C and then, the air is expanded to 140 kPa with a reversible adiabatic process. Calculate the speci c work (kJ=Kg) done by the gas. Assume calorically perfect gas
Wednesday, March 31, 2010 at 11:43am by john

thermo
equal masses of ice at 0 oC, water aat 50 oC and steam at 100 oC are mixed and allowed to reach equilibrium. what will be the final temp of the mixture? and what percentage is the water and what percent will be steam??
Friday, November 5, 2010 at 1:55am by holly

Thermo engineering
torque= force*radius power= torque*angular speed where angular speed= 300*2PI/60 rad/sec this will give you power in watts.
Tuesday, May 10, 2011 at 3:18pm by bobpursley

Physics - electricity
A thermo junction of iron and copper connected to a galvanometer cannot be used to measure temp above about 450K, whereas one of iron-constantan may be used to at least 875K. What is the explanation? Is it possible that melting at the junction point is a limiting factor?
Tuesday, April 17, 2007 at 3:34am by Damilola

11th grade- Long thermo problem - needs physical chem teacher
You can get the heat Q released to the water easily. I suppose you figure a free expansion to the maximum cylinder volume, then use PV = nRT on all the constituent partial pressures. I am no physical chemist though and hope one shows up.
Friday, January 2, 2009 at 6:12pm by Damon

Thermo engineering
The driveshaft of a building’s air-handling fan is turned at 300 RPM by a belt running on a 0.3-m-diameter pulley. The net force applied by the belt on the pulley is 2000 N. determine the torque applied by the belt on the pulley, in N.m, and the power transmitted, in kW.
Tuesday, May 10, 2011 at 3:18pm by Justin

science
thermo dynamic variables which are not path depends are called independent variables. for example- pressure, temperature, volume, number of moles are independent variables. Only work and energy is dependent variables. they are path dependent.
Sunday, March 6, 2011 at 8:08pm by kinjal

Science
Warm air often goes to the upper parts of the house. Whar is the name of the process by which air moves and carries heat energy with it ? Since this is not my area of expertise, I searched Google under the key words "heat convection" to get these possible sources: ...
Tuesday, April 24, 2007 at 11:45am by ASD

Thermo
In an isothermal reaction (either reversible or irreversible), DELTA T is constant..hence zero since temperature remains constant, can we also assume that heat is also zero? if so, how then is an isothermal reaction different from an Adiabatic one?
Friday, March 12, 2010 at 2:18pm by Kim P

Thermo
You are quite right. The heating value of coal varies with type, from 15,000 to 27,000 kJ/kg for soft coals, reaching 31,000 for coke and 34,000 for anthracite. They may want you to use the heat of formation of Carbon (graphite). It is a poorly constructed question. The ...
Sunday, March 18, 2012 at 8:04am by drwls

physics - another thermo problem
A bicycle pump is a cylinder 20 cm long and 3.0 cm in diameter. The pump contains air at 25.0 C and 1.0 atm. If the outlet at the base of the pump is blocked and the handle is pushed in very quickly, compressing the air to half its original volume, how hot does the air in the ...
Thursday, September 18, 2008 at 5:40pm by Nik

Chemistry
Ethanol, C2H5OH or C2H6O, is mixed with gasoline and sold as gasohol. Given the following thermo-chemical reaction, calculate the kilograms (kg) of CO2 produced when enough ethanol is combusted to provide (or give off) 369 kJ of heat: C2H5OH (l) + 3 O2 (g) --> 2 CO2 (g...
Tuesday, July 12, 2011 at 7:41pm by Robert

Design and Technology
Thank you for using the Jiskha Homework Help Forum. Although your subject is definitely NOT in my area, hopefully one of these Websites will answer that for you: 1. http://www.freepatentsonline.com/4339400.html 2. (part II of #1): http://www.freepatentsonline.com/EP1284756....
Saturday, September 13, 2008 at 4:51am by SraJMcGin

Physics-Thermo
Imagine a 600 g of water at 70oC in a piston-cylinder device. Initially, the 9-kg, 13-cm diameter piston rests on two stops such that the water occupies a volume of 0.2 m3. Heat is transferred to the system until the water is completely vaporized. Take the atmospheric pressure...
Monday, March 26, 2012 at 9:54am by sara

thermo
four hundred cubic centimeters of a gas at 740mm Hg absolute and 18 degree celcius a process until the pressure until the pressure becomes 760mm Hg absolute and the temperature o degree celcius. what is the final volume of the gas
Wednesday, October 3, 2012 at 6:43am by 111111

thermo
The sum of the heats gained will be zero. Heat gained by steam matter + heat gained by ice matter =0 m*Lv+m*cwater*(Tf-100)+m*Lf+m(Tf-0)=0 you know the two latent heats (vaporization, fusion, specific heat water) and mass divides out. Find Tf
Friday, November 5, 2010 at 1:42am by bobpursley

environmental science
Thank you for using the Jiskha Homework Help Forum. Try the following: 1. http://en.wikipedia.org/wiki/Second_law_of_thermodynamics 2. http://www.secondlaw.com/ 3. http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html 4. http://www.emc.maricopa.edu/faculty/farabee/...
Monday, March 10, 2008 at 3:38pm by SraJMcGin

Chemistry (Thermo)
Thank you, I still can't seem to get the last one. We are given our data in kJ/mol So would q = n (heat fusion ice + heat sublimation ice + (heat capacity water x delta T)) ? We also don't have the heat vaporisation value. Only for sublimation - is it the same? They ...
Friday, September 10, 2010 at 10:25am by Amy

science
Whar is the name of the process by which hrat energy is tranferred through the walls of the house ? Conduction, convection, and radiation are the three ways energy is transferred. Look up each in your text/notes/dictionary and make your choice. In case you are posting under ...
Tuesday, April 24, 2007 at 11:42am by QAQA

college (physics thermo)
A 1.20 mol sample of an ideal diatomic gas at a pressure of 1.20 atm and temperature 380 K undergoes a process in which its pressure increases linearly with temperature. The final temperature and pressure are 680 K and 1.83 atm. (assume 5 active degrees of freedom) b. ...
Monday, February 2, 2009 at 2:33pm by dennis

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

Science
What is the name of the process by which energy reaches the walls of the house directly from the sun ? In case you are posting under difference addresses, please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time ...
Tuesday, April 24, 2007 at 11:46am by 12345

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

physics - another thermo problem
In an isentropic adiabatic process such as this, P*V^1.4 is a constant for diatomic gases such as air. Since V decreases by a factor of 2, P2/P1 = (V1/V2)^1.4 = 2.639 Use the perfect gas law to compute T2 P1*V1/T1 = P2*V2/T2 T2/T1 = (P2V2)/(P1V1) = 2.639*(1/2) = 1.3195 T2 = 1....
Thursday, September 18, 2008 at 5:40pm by drwls

Chem Question (thermo)
Calculate ΔG at 25 ºC for a reaction in which Ca2+(aq) combines with CO32–(aq) to form a precipitate of CaCO3(s) if the concentrations of Ca2+(aq) and CO32–(aq) are 0.023 M and 0.13 M, respectively. (ΔGº = –47.94 kJ) A. –62.3 kJ/...
Thursday, March 1, 2012 at 6:21pm by M

Chemistry (Thermo)
b. q = mass x heat fusion q about 32,723,000 J heat fusion about 334 J/g Solve for mass ice. You should confirm the 334 value. c. q = [mass ice x heat fusion ice] + [mass water x specific heat water x delta T] Let mass ice = mass water = x and solve for x. d. Same procedure ...
Friday, September 10, 2010 at 10:25am by DrBob222

Chemistry (Thermo)
High quality coal (anthracite) is almost pure carbon. The combustion of carbon to carbon dioxide releases 393kJ per mol of carbon burnt. If 1kg of anthracite is burnt: a) How much heat is released? b) How much ice (in kg) at 273K could be melted to give water at 273K? c) How ...
Friday, September 10, 2010 at 10:25am by Amy

thermo
Saturated water vapor at 100 kPa jets into a pitcher containing 0.17 Kg of water initially at 278 K. If steam ow rate is 4 gm/min, estimate how long it takes to heat the water to 322 K. Assume the process is at constant pressure (at 100 kPa) and kinetic energy of the incoming ...
Wednesday, March 31, 2010 at 11:43am by john

Thermo
one more question: a worker cleans a railroad car with steam of 15000ft^3 car on inside, t=240F P=14.7psia of steam. the car is closed. the steam inside cools until P=12 psia, at which time salad oil is added to tank. find a. heat transfer from steam during cooling, b. amount ...
Monday, March 15, 2010 at 10:32pm by spencer

IPC
Zeroth Law of Thermodynamics = two objects in thermal equilibruim will have no net heat flow between them. **this only means that when two objects are in thermal equilibrium (or their temperature is the same/equal), heat is being transferred. this is a consequence of the ...
Tuesday, May 3, 2011 at 10:06am by Jai

thermo
You may find some of the following links helpful: http://search.yahoo.com/search?fr=mcafee&p=equal+masses+of+ice+at+9+oC%2C+water+at+50oC%2C+steam+at+100oC+are+mixed+%26+allowed+to+reach+equilibrium%2C+what+is+the+final+temperature+and+the+percentage+of+water+%26+steam Sra
Friday, November 5, 2010 at 1:55am by SraJMcGin

more thermo
For the following question I was able to find the heat transfer and the entropy but I am having trouble finding the work done. When i solved delta E = Qnet - Wnet I got Win = Wout but Im not sure that is correct. I think that i need to solve for the final temp and pressure but...
Monday, June 18, 2007 at 6:30am by jody

Chem.
Nitrogen oxide (NO) has been found to be a key component in the many biological processes. It also can react with oxygen to give the brown gas NO2. When one mole of NO reacts with oxygen, 57.0 kJ of heat is evolved. a) Write the thermochemical equation for the reaction between...
Monday, January 29, 2007 at 6:39pm by Christopher

thermo
For the following problem... I found the second pressure by solving P1V1/T1 = P2V2/T2. The Volumes is const so those cancel and then i am able to find the P2. From there i looked at the 1st law and came up with delt U = Qin which = mCvdelta T but that is where I am stuck. Can ...
Sunday, June 17, 2007 at 5:35pm by jody

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