Heat capacity Definition and 419 Threads

So our teacher wants us to find the temperature of a flame of a bunsen burner. To do so, he told us to do the following: Heat an aluminium block of known mass (160g), but unknown initial temperature. Drop it in a beaker with 500 ml of water, of known temperature (22 degrees) and let the...

Homework Statement Hi there. I'm having some trouble on solving this exercise, which you can find on Callen 2nd edition. A simple fundamental equation that exhibits some of the qualitative properties of typical crystaline solids is: u=Ae^{b(v-v_0)^2}s^{4/3}e^{s/3R} Where A,b, and v0 are...

Homework Statement in the absense of bearing friction a winding engine would raise a cage weighing 1000 kg at 10m/s, but this is reduced by friction to 9 m/s, how much oil, initially at 20 C is required per second to keep the temperature of the bearing down to 70 C (specific heat capacity...

the difference between the entropy and the heat capacity? they are very similar! hello ... as we all know that specific heat capacity = joule/ k entropy = joule/k they are same in units Q= m Cv dT Q/dT=m Cv...1 dS= dQ/T ...2 from 1 & 2 dS= m Cv .....??… I'm now confused...

I am doing a lab about specific heat. i have a cup of boiling water which i put 5 metals into, and a cup of warm water which sits at 22 degrees celcius. i am to record the difference in temperature as i am using the equation Q = mc (delta) T for part one, and then i am using the equation C = Q/m...

Homework Statement How can you calculate the specific heat capacity of an unknown metal? In my question the metal with a mass of 50g and a temperature of 200 degrees celsius was placed in 125 g of water with an initial temperature of 20 degrees celsius. After the simulation and the metal...

Homework Statement This was a LAB assignment. I need to find the specific heat capacity of a given metal (Cu in this case) in water, I have the following observations. Mass of water: 249.14g = 0.24914 Kg Initial temperature of water: 18 C Initial temperature of metal: 100 C Specific heat...

Homework Statement [/b] Debye considered atoms to oscillate from 0 up to a nu max. It is explained further in the text that the complication (i.e., not all atoms oscillating at same frequency as shown in Einstein's formula) is accounted for, by averaging over all the frequencies present...

Homework Statement Given the perfect gas molecules with permanent electrical dipole moment u in the field \epsilon. The potential energy is U = -u\epsilon\cos\Theta Derive the additional effect of \epsilon on the heat capacity. I need some hints, please help. Thanks.

Homework Statement 1. Calculate heat lost by the hot water in the calorimeter. Initial temp: 22.90 C Finial temp: 23.25 C Density: 1.00 g/mL specific heat capacity: 4.18 J/gK Homework Equations qmetal=-(qwater+qmetal) q=m C dT The Attempt at a Solution When i use the second...

I understand that the heat capacity of something run at constant volume is lower than at constant pressure, as at constant pressure the substance can expand, so some of the energy put into the system is used for work. If i have two identical systems and heat them under constant pressure...

We have the parameters,current =10^-3A,V=15kv,number of electrons=6.25 X 10^15,velocity=7.3 X 10^7,specific heat capacity of the liquid=2 X 10^3,c=3 X 10^8,h=6.63 X 10^-34,mass of electron = 9.11 X 10^-31. Now the question says,in an x-ray tube having those parameters,find the rate at which...

Homework Statement 1.0 g of water at 28 degree celcius is placed into a 200g aluminium can at 300 degree celcius. What is the temperature of the aluminium can after all the water vapourises? Given the specific heat capacity of aluminium, 900 J/kg/degree celcius and water, 4200 and specific...

Homework Statement This is a problem I made myself and it's really confusing me. You have 100mL of water and place it in a calorimeter of low specific heat capacity. You put another 100mL of water in another calorimeter of high specific heat capacity. Assume in both instances that the water is...

Hello PF, Is the following calculation correct for the amount of time it would take to raise the temperature of a given mass of material? Q = heat in J W = watts m = mass in kg c = specific heat in J/kgC Tf = temperature final Ti = temperature initial Q = m * c * (Tf - Ti) m = 5...

1. Propane vapour (1kmol) at a pressure of 40 bar and 230 C expands adiabatically to 0.25 bar and 95 C. Determine a)W, b)Delta S, c)The amount of work obtained if the expansion were done reversibly from the same initial conditions to the final pressure of 0.25bar 2. I am not sure how to...

Homework Statement The question asks whether it is always true that dU=C_VdT and their answer is no, because from the 1st law of TD we derive that: dU=C_VdT+\left(\frac{dU}{dV}\right)_TdV However, if we hold the volume constant, dV=0 and therefore the second term disappears, is this...

I have the equation for heat capacity for constant volume and pressure. Cv = Cp -R So for Cp I have the units J/k and for R the units are J/k mol. So my question is related to that mol. Is it right that I need to get rid of that mol? if so how? Does it involve Avogadro's Constant? Or do...

Homework Statement The carbon-dioxide has nondegenerate vibrational energies εr=（h/2π）ω(r+1);r=0,1,2..., where ω=(1.26*10^14)s^-1. What is the contribution of these vibrational modes to the molar heat capacity of carbon-dioxide gas at T=400K? Homework Equations...

The question involves testing the Specific Heat Capacity of an aluminum block, using the equation: Q = m x Specific Heat Capacity x Change in Temperature. Two experiments are performed using the same power of the heater and the same mass of the object and a very similar change in...

Homework Statement The experiment was that we heated a beaker with water in it, and also a type of metal for around 5 minutes so that the metal becomes the same temperature as the water. We then dropped that heated metal into a stryofoam cup containing 189.10g of water in it. mass of...

Trying to determine the amount of energy required to heat a specific volume of air by a certain change in temperature. So far this is what I gotten. Vol: 10,000 cubic feet = 283.17 m^3 Orig Temp: 0C (32F) Final Temp: 21.1C (70F) deltaT: 21.1 K or C Density of air @ 0C: 1.293 kg/m^3 Cp...

Hi, I just did a specific heat capacity test using a calorimeter, and the specific heat capacity I found (using heat gained = heat lost) is less than the real value. The problem is, I expected it to be more. I mean heat will be lost through the calorimeter, meaning that a greater amount of...

Hi there! So I'm aware that the phonon contribution is proportional to T^3 and for electrons it is T (this is for metals where the first result comes from the Debye model). I was wondering where the electron contribution is derived from and why it is such a low dependence.

When using the equipartition theorem to derive the heat capacity of an ideal gas, you have \left\langle H \right\rangle=\left\langle \frac{1}{2}m\left(v^{2}_{x}+v^{2}_{y}+v^{2}_{z} \right) \right\rangle and each degree of freedom contributes 1/2 kT to the total energy and 1/2 k to the total...

Homework Statement The cream is kept at 5 ºC in the lorries. It is pumped into silos, where it is pre-heated before being pasteurized. The silos are jacketed, and hot water is pumped through the jacket. Assuming no losses, if 300 kg of water at 90ºC enters the jacket and exits at 60 ºC...

Homework Statement Just wanted to find some clarity regarding this subject. In my textbook, it states that Q = nCvdT for constant volume and Q = nCpdT for constant pressure. However, one of the TA's in my classes were telling us how dU = nCpdT for constant pressure and dU = nCvdT for...

Homework Statement In the temperature range from 60 K to 80 K, a certain amount of liquid has a temperature dependent heat capacity that is given by Cp = 20 J K−1 + T × 0.5 J K−2. Determine the entropy change resulting from heating this sample from 60 K to 80 K. Homework Equations...

Homework Statement I'm needing to write a program for thermodynamics, but before I can write the program, I need to find formulas for the heat capacity of a few substances: Al, Fe, BaTiO3, and Polyethylene. Ideally, I'm looking for equations that explain this behavior between 298K and 600K...

Homework Statement At 25C Cu metal (at. wt. 63.54 g/mol) has a molar heat capacity of 24.4 J/molK. The density of Cu is 8.949g/cm^3 at 0C and 8.904 g/cm^3 at 100C. Assuming that Cp is temperature independent, calculate Q, W, deltaU and deltaH when 100grams of Cu metal are heated from 0C to...

I'm fascinated with physics and probably know at least the nature of any effect or object in classical physics, but um... I have never in any textbook or article seen mention of what determines the specific heat capacity of a given substance. Which is kinda peculiar and confusing at the same...

Hi Everyone :smile: I have to create an experiment for my assignment in Physics. I've chosen to do something about Specific Heat Capacity. A boy in my class is also doing SHC so I wanted to make mine a little different from his. I've just recently joined physics (never done it before)...

when working this out, is it just Cv + Cp? giving 4nR? thanks

Homework Statement The temperature at the top of a popular waterfall is 22.0 degrees celcius. The temperature at its base, 210 m lower, is 22.5 degrees celcius. 1)Caluclate the specific heat capacity of the water. 2) If the waterfall was twice as tall, determine by how much the water...

Homework Statement 3.00 kg of molten lead is allowed to cool until is has solidified. It is found that the temperature of the lead falls from 605 K to 600 K in 10 s, remains constant at 600K for 300 s, and then falls to 595 K in a further 8.4 s. Assuming that the loss of heat energy remains...

I'm working from Feynman's definition of internal energy for the Debye theory of heat capacity. I'm trying to use that to derive the normal definition of heat capacity that I've seen. But I'm running into a problem. Note, in the following V_0 is frequency, whereas V is volume (that's how Feynman...

just trying to get my head around heat capacity here for an experiment; if conducting a reaction in an adiabatic vessel, of which its material has a finite heat capacity, does this mean that if sufficient heat is produced within the vessel (through a chemical reaction), that the adiabatic...

hey for this question If a 2kg sample of aluminium absorbs 64.4 kJ of heat from its surrounds by how much does its temperature increase the answer is 65.1 how? i got 32.5 q=mcT T=q/mc=(64.6x10^3)/(2000x.9930) also same for this question If 0.5g of an organic compound is completely...

Homework Statement The molar heat capacity at a constant volume of a solid at low temperatures T << Td, where Td is the Debye temperature is given by: C_v = 464(\frac{T}{T_d})^3 Consider Td = 281 K for the NaCl. (a) Calculate the average molar heat capacity \bar{C_v} of the NaCl between...

Homework Statement 0.1kg of ice was added to a lemonade of mass 330g at an initial temperature of 28 degree celcius and it completely melted. Considering only the lemonade and ice cubes, calculate the final temperature of the lemonade. Given: specific latent heat of fusion of ice= 336000...

a 210 heater is places in 2 kg of water. What temperature rise is produced if the heater is switched on for 200 seconds? I need your help please.

A monatomic ideal gas undergoes a process in which the ratio of P to V at any instant is constant and equals to 1. What is the molar heat capacity of the gas? (A) 4R/2 (B) 3R/2 (C) 5R/2 (D) 0

Homework Statement Blood can carry excess energy from the interior to the surface of the body, where the energy is dispersed in a number of ways. While a person is exercising, 0.8 kg of blood flows to the surface of the body and releases 1300 J of energy. The blood arriving at the surface...

Homework Statement I heated 50mL of water in a Dewar and measured the temp. change with time. however, this only gives me the heat capacity of the system. I again measured but with 100mL of water, in an attempt to correct for the unknown heat capacity of everything but the water. However...

Homework Statement In order to find the specific heat capacity of an unknown material, a 50g piece is heated to 80 degrees Celsius and fully immersed in a well insulatyed calorimeter filled with 100g of water at 10 degrees Celsius raising the temperature of the water by 5 degrees, the heat...

Q. Thermal energy is supplied to a melting solid at a constant rate of 2000 W. Calculate the mass of the solid changed to liquid in 2.0 minutes. Assume that the specific latent heat of fusion of the solid is 95 000 J kg-1 and that heat exchange with the surroundings may be neglected. I was...

Homework Statement The following data is obtained: Weight of ice cube added 20 g Weight of copper calorimeter 80.5 g Weight of water in calorimeter 105 g Initial temp of ice cube -18 deg C Initial temp of water 23 deg C Final temp of water 6 deg C Specific Heat Capacity copper 385 J...

can you please state some liquid which is a good heat conductor (which have low specific heat capacity)

Homework Statement To summarize, I am given 6 objects and their corresponding specific heat capacity and thermal conductivity values. All objects have the same mass. The question is asking me to rank the objects based on temperature if they are put in a hot oven until they reach thermal...

Homework Statement Finding the specific heat capacity of an unknown metal. A cylinder was placed into boiling water, originally at 24.2 C. The heat transferred from the metal, and the water then was 29.5 C. Original Temperature-24.2 C Temperature after the metal has been placed into the...