What is Heat capacity: Definition and 437 Discussions

Heat capacity or thermal capacity is a physical property of matter, defined as the amount of heat to be supplied to an object to produce a unit change in its temperature. The SI unit of heat capacity is joule per kelvin (J/K).
Heat capacity is an extensive property. The corresponding intensive property is the specific heat capacity, found by dividing the heat capacity of an object by its mass. Dividing the heat capacity by the amount of substance in moles yields its molar heat capacity. The volumetric heat capacity measures the heat capacity per volume. In architecture and civil engineering, the heat capacity of a building is often referred to as its thermal mass .

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  1. T

    Time for a steel die to reach temperature

    Hello. I will be doing some experiments with boron steel. The idea is to heat a steel specimen (200x20x1,5 mm dimensions) to 950°C and then quickly transfer it from the oven to the die at room temperature. When the specimen reaches the steel die it will supposedly be at around 800°C. At this...
  2. T

    Electron Heat Capacity Integral

    1. The answer to this problem is easy when plugged into mathematica it's (pi^2)/3. I am trying to integrate it by hand however and can't figure out how to start it. I also can't find any other attempts of it online (our professor says we can just look it up if we can find it). [(x^2*E^x)/(E^x...
  3. K

    Heat Capacity of NaCl: 500K-1074K & 1074K-1500K

    Homework Statement The heat capacity of the solid NaCl from 500 K to 1074 K is given by [52.996 J*K-1*mol-1 – (7.86*10-3J*K-2*mol-1)*T + (1.97*10-5J*K-3*mol-1)*T2 ] and that of liquid NaCl from 1074 K to 1500 K is given by [125.637 J*K-1mol-1 – (8.187*10-2 J*K-2*mol-1)*T + (2.85*10-5...
  4. K

    Standard enthelpy of formation

    Homework Statement I have the following task: The Standard enthalpy of formation of gaseous H2O at 298K is -241.82 kJ mol-1. Estimate its value at 100 °C given the following values of the molar heat capacities at constant pressure: H2O (g): 33.58 JK-1mol-1, H2 (g): 28.84 JK-1mol-1, O2 (g)...
  5. G

    Does the heat capacity change for a metallic system?

    In class we derived the relationship between temperature and heat capacity for the Debye model. We found that in 3D the heat capacity is proportional to temperature cubed. My question is, would this relationship change in a metallic system?
  6. MDM

    Calculating the Heat Capacity of Diamond

    Homework Statement Heat capacity is the ability of the material to store energy internally. If I completely insulated diamond and I put heat into it, It would have the ability to store 6.57 (Joules/mole) per degree Kelvin. Use this formula q=Cp (ΔT/ Δt) where q is heat in Watts, ΔT is...
  7. K

    Specific heat capacity coursework

    Homework Statement earlier today i was doing some coursework to find the specific heat capacity of an unknown metal by submersing 100g / 0.1kg of the metal in boiling water above 75°C and record the temperature after 30 seconds (θm). we then had to transfer the the metal from the boiling water...
  8. C

    Specific heat capacity (the very basics)

    The specific heat capacity is the amount of heat energy needed to raise 1 kg of a substance by 1 °C. Q. So the specific heat capacity of water is 4.184kJ (given that 1 Cal (large calorie aka the kg calorie aka the food calorie) is required to do the same, ie, raise the temperature of 1 kg of...
  9. Pouyan

    Specific heat capacity of calorimeter

    I've got a problem: A piece of copper with mass m1 = 800 g and temperature t1 = 80 ° C is placed in a container with good thermal insulation. The vessel initially contains water with mass m2 = 500 g temperature t2 = 20 C. What is the calorimeter (including thermo meter) heat capacity if the end...
  10. V

    Specific heat capacity of metal

    Homework Statement I have 1.5 kgs of silicon with temperature 40 degrees celsius. It is dropped into 3 kgs of water holding temperature 25 degrees celsius. The system is heat isolated from the environment and the final temperature of the system is 26.2 degrees celsius. I need to find the...
  11. R

    Do Refrigerants have more heat capacity than water?

    I was reading this report prepared by PNNL which says (page 16): "Using refrigerant to deliver heating and cooling requires less energy because of the larger heat capacity of the refrigerant relative to air and even water. Less mass flow is needed to deliver the same amount of heating or...
  12. shrutiphysics

    Molar Heat Capacity: Find Value of k

    Homework Statement A diatomic ideal gas is heated at constant volume until its pressure is doubled. It is again heated at constant pressure until its volume is doubled. The molar heat capacity for the whole process is kR. Find the value of k. Homework Equations ans is k=19/6. p/t=constant...
  13. L

    Specific heat capacity of gases

    Homework Statement Figure shows two rigid vessels A and B, each of volume 200 cm3 containing an ideal gas (Cv = 12.5 J/mol-K). The vessels are connected to a manometer tube containing mercury. The pressure in both the vessels is 75 cm of mercury and the temperature is 300 . (b) 5.0 J of heat...
  14. Pouyan

    Problem with heat capacity of thermal system

    Homework Statement a) a styrofoam cup contains 200g of water at 20 C.What will be the equilibrium temp of the system after 100g of silver,initially at 300 C,has been added?you may assume that the heat capacity of the cup is negligible and that no heat is lost to the surroundings. (b) a further...
  15. D

    Specific heat capacity and changing volume

    Hello everyone, I just need some help understanding some thermodynamics. So I have 0.25 kg of helium which is compressed from an initial state in a polytropic process with n = 1.3. So its given the change in volume and the initial pressure. I need to find the change in internal energy. I am...
  16. R

    Specific heat capacity ; voltage ; heating water

    Hi, I am doing an experiment on the factors affecting the time to heat water from a set temperature to another, eg 20 to 35 deg C. 1. First, I have insulated the beaker properly, to minimise heat loss. I have connected a heating element to heat the water. Connected multimeter, give the voltage...
  17. H

    How Do You Calculate the Final Temperature of a Glass Pot and Oil?

    I recently encountered this problem in class "A glass pot of mass 0.6kg contains 1.2kg of oil at 15 degrees Celsius. If 214kJ of energy is supplied to it, what is the final temperature of the pot and oil? ( The specific heat capacity of glass is 700 J kg-1 °C-1, and the specific heat capacity of...
  18. S

    Heat capacity of water -- experimental determination

    Homework Statement A quantity of water in a beaker of negligible thermal capacity is cooled to a few degrees below freezing point. The beaker is then placed in a warm room, and the times recorded at which it is at various temperatures as it gradually warms. The observations were...
  19. Muhammad Nauman

    Specific heat capacity of Gd5Si3 and GdSi

    Hello alll. I am Muhammad Nauman, Research Associate in COMSATS university islamabad pakistan and new in this group. I need Specific heat capacities of Gd5Si3 and GdSi. Can someone help me??
  20. W

    Need clarification on adiabatic process and heat capacity

    In class we're currently learning about reversible and irreversible adiabatic processes. For reversible process, we got dq=0, so dU = dw = -P*dV = Cv*dT. What I don't get is where did the Cv*dT come from? I remember q=C*dT, but dq = 0 so I'm not sure what that means? Also, where does Cv*dT...
  21. T

    Einstein's heat capacity model .and law of corresponding

    Homework Statement B/c the textbook mentions that Einstein's heat capacity equation obeys a law of corresponding states...but, I don't really understand how this can be...I've tried to figure out, to no avail...so, any help would be welcome! Homework Equations Cv/NkB =...
  22. D

    Specific Heat Capacity of water in a kettle

    Homework Statement mass, m, of water in kettle 1.5 kg power rating, P, of kettle 2.1 kW time interval, t, for heating 322 seconds starting temperature 4 °C = 277 K finishing temperature 100 °C = 373 K temperature change, ΔT 96 K electrical energy supplied, E = P × t...
  23. L

    Molar heat capacity at constant volume

    Hi everyone, If you know the temperature rise of 2 moles of an ideal gas when a known amount of energy is transferred to it as heat, (hence are able to calculate cv by dU/dT); is the molar heat capacity simply half this value as it is half the number of moles?
  24. A

    Why Must a Calorimeter Be Saturated with Water Vapor?

    Homework Statement A bomb calorimeter is used to measure the overall heat output. It is calibrated by burning 1.00g of methanol (Change in enthalpy of combustion- 715 kJ mol–1) in O2 which produces a temperature rise of 8.40 K. Use this information to determine the heat capacity of the...
  25. M

    Vortex Tube for cabinet cooling

    Hi, I'm a mechatronics student and I am currently working on a project on the effectiveness of a vortex tube to cool a cabinet. The cabinet has a thermostat inside and if the temperature exceeds a threshold, an air compressor is turned on, causing the vortex tube to cool the cabinet. The cabinet...
  26. U

    Heat capacity ratio yields inconsistent results

    Homework Statement A Gas is in a Volume V0 = 1 Liter at Pressure p0 = 3 bar. Isochoric Heating using the Heat Q1 = 182 J, the pressure raises to p1 = 6.34 bar. Gas is reset to inital state. Isobaric Heating using the Heat Q2 = 546 J, the Volume increases to V2 = 3 Liter. Calculate Cp/CV...
  27. P

    Thermal conductivity and heat capacity

    Using kinetic theory, we can derive an expression for the thermal conductivity of a gas to be κ=nCmoleculeλ<v>/3 where n is the number density of the molecules in the gas, Cmolecule is the heat capacity of a single molcule (i.e the heat that must be given to each molecule to raise the...
  28. S

    Calculating Mass Increase of Coffee Using Specific Heat Capacity

    Homework Statement Using coffee (specific heat capacity of 3.98 x 10^3 J/kg °C) calculate the increase in mass if you raised the temperature of a 353 g cup of coffee from 34° C to 97°C. Homework Equations Q=mcΔt The Attempt at a Solution I believe I just need to solve for m. However I have...
  29. A

    Calculating Heat Capacity of Calorimeter

    Need a little help, as I seem to have gotten confused. Looking over past exam questions for the heat capacity of a calorimeter, this one is the one I am looking at : A sample of the sugar fructose (C6H12O6) of mass 0.900 gwas placed in a calorimeter and ignited inthe presence of excess oxygen...
  30. N

    Heat capacity of magnetic dipole in magnetic field

    edit: The title is misleading, sorry. Originally I wanted to ask a question about the heat capacity but I figured it out and changed the question while forgetting to change the thread title.. Hi. OK, assume we have a classic magnetic dipole in a magnetic field with ##H= - \vec{\mu} \cdot...
  31. A

    Heat Capacity of Nanoparticles - Experimental Determination

    I know little about the experimental measurements of heat capacity. I can see you'd need to know both how much energy you've transferred to a nanoparticle, and measure the temperature change resulting to ascertain it. This brings me to my questions: How effective is laser heating of...
  32. G

    Understanding the Energy Modes of Springs in a Solid

    Hello everyone ! I'm a bit confused about assumption that's made in "Concept in Thermal Physics ; Stephen J. Blundell and Katherine M. Blundell" page 205. It is stated that " Consider a cubic solid in which each atom is connected by springs (chemical bonds) to six neighbours (one above, one...
  33. M

    Heat Capacity and Thermal Equilibrium

    Homework Statement A 3.50-kg block of iron initially at 8.00 × 10^2 K is placed on top of a 6.25-kg block of copper initially at 4.00 × 10^2 K. Assume the blocks are thermally insulated from their surroundings but not from each other and that they constitute a closed system. How much energy is...
  34. K

    Heat capacity in 3-level systems

    Homework Statement I uploaded a picture of the problem here: http://imgur.com/kD35ROl Sorry about the norwegian text, the problem is this: The three figures with red lines indicate three different energy levels of a system in thermal equilibrium with a reservoir of temperature T. The three...
  35. K

    Finding the Specific Heat Capacity of a Potato

    Homework Statement So I've been trying to find the specific heat capacity of the potato for a while and keep coming up with an outrageous number (over 700,000 J/kgC) Here's what I've found mass of potato = 0.15kg initial T of potato = 18 degrees C final T of potato = 83 degrees C (is this not...
  36. R

    Calculating Specific Heat Capacity: Solving for Unknown Variables

    Homework Statement When 1.25 kg of a cold metal at a temperature of 263 K was immersed in 1.43 kg of water at a temperature of 365 K, the final temperature was 336 K. What is the specific heat capacity of the metal? Homework Equations Q=mc∆t -Q=Q[/B] The Attempt at a Solution The answer...
  37. W

    Degeneracies in Optical Modes in relation to Heat Capacity in a Solid

    Technically I'm supposed to have a total of 8 optical modes but only 4 of them were seen in a solid (by spectroscopy). So I suspect there's some degeneracies and symmetries involved, but I don't know which ones. I have two sets of assigned degeneracies: frequency; degeneracy set 1; degeneracy...
  38. E

    Molar heat capacity and Degrees of freedom

    Homework Statement The diagram shows the molar heat capacity of an ideal diatomic gas and the number of degrees of freedom at different temperatures. Explain why there are 3 discrete plateaus and why the curve is smooth and leaning between them. Homework Equations - The Attempt at a Solution...
  39. MexChemE

    Internal energy, enthelpy and heat capacity

    Hello PF! I have some questions regarding these concepts. First of all, are the following expressions valid for any case? i.e. any kind of process, like isochoric, isobaric. \Delta U = \int C_v \ dT \Delta H = \int C_p \ dT Or is the ΔU expression only valid when dV = 0, and ΔH when dP = 0...
  40. mef51

    [Thermodynamics] Heat Capacity for Polytropic Process

    Consider an ideal gas. For a polytropic process we have ##PV^n = const##. Different values of ##n## will represent different processes; for example isobaric (##n=0##), isothermal (##n=1##), and isochoric (##n=\infty##). The Wikipedia article on polytropic processes states that the specific heat...
  41. A

    Specific Heat Capacity of water

    The specific heat capacity of water is accepted to be roughly 4.18 J/gK. How would the specific heat value of a given water sample be effected when sediments and other forms of particulation, such as iron oxide from rust, are present? Would the mixture have a higher specific heat capacity value...
  42. S

    Specific heat capacity of copper

    Homework Statement A solid copper cylinder, 50 mm long and of 10 mm radius, is suspended in a vacuum calorimeter. Wound on the cylinder is a length of fine copper wire which is used as heater and resistance thermometer. Initially the resistance of the heater is 100.2 Ω. A current of 100 mA is...
  43. F

    Specific Heat Capacity: Comparing Spheres

    How do I know which one of these two spheres have more specific heat capacity?
  44. A

    Specific heat capacity of liquid form of permanent gases.

    Hi, The permanent gases like Nitrogen, Helium etc. have more specific heat capacity as liquid than their gases. Seemingly degree of freedom should reduce in liquid form, and therefore, specific heat capacity must reduce in liquid form. But this isn't the case. I remember reading somewhere...
  45. S

    Specific heat capacity - heating ice/water

    Homework Statement A pot on a stove burner contains 10kg of water and an unknown mass of ice at equilibrium at 0degC at time = 0min. During the first 50mins, the mixture remains at 0degC. From 50 to 60mins the temperature increases to 2degC. What is the initial mass of ice? Ignore the heat...
  46. S

    Specific heat capacity - heat energy transfer

    Homework Statement Find the mass of water that vaporizes when 3.39 kg of mercury at 243 °C is added to 0.476 kg of water at 90.0 ° Homework Equations q=mcT, q=mL The Attempt at a Solution When vaporising T=100degC. Heat lost by mercury = heat gained by water. 3.39kg x 139J/kg/C x...
  47. H

    Comparing Specific Heat Capacity of Metals A & B in Wax Block

    Homework Statement the answer is c) but i can't figure why ! is the more heat capacity substance lose and gain energy faster than the other one so it take more energy to get it's temperature raised by the same amount because it lose most of it very fast during the heating process ?
  48. M

    Vibrational Excitation and Heat Capacity

    Homework Statement (a) Given V, α, κT, μJT, and CP, calculate CV at 90.0 bar and 308 K for carbon dioxide gas. (b) If carbon dioxide's vibrations were fully excited, then CV would be 4R. What's the percent vibrational excitation at 90 bar and 308K? Homework Equations Both constant pressure...
  49. N

    How to determine specific heat capacity

    I have been looking for specific heat capacities of certain materials such as steel but i can never find a solid answer, so i figured i would test it myself, how would one test specific heat capacities?
  50. P

    The specific heat capacity at constant volume for liquid isopropanol?

    Hey I am a physics student, and not so familiar with chemistry. I have a huge problem, because I have to find the following 3 values for liquid isopropanol: 1. The specific heat capacity at constant volume 2. The specific heat capacity at constant pressure 3. Volumetric Isobaric...
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