Specific heat Definition and 481 Threads

Homework Statement Please look at the below images which is the derivation of the relation between the internal energy of an ideal gas and the molar specific heat at constant volume. (Snaps taken from Fundamentals of Physics Textbook by David Halliday, Jearl Walker, and Robert Resnick) As...

Homework Statement A satellite to reflect radar is a 3.5-m-diameter, 2.0-mm-thick spherical copper shell. While orbiting the earth, the satellite absorbs sunlight and is warmed to 50 °C. When it passes into the Earth's shadow, the satellite radiates energy to deep space. You can assume a...

Hi! I am using a Zn-Mg alloy (52% and 48% respectively) as a phase change material in a thermal energy storage system, but I have been unable to track down important properties, such as specific heats and thermal conductivity. Is there any way to approximate these relatively accurately given...

NO TEMPLATE BECAUSE SUBMITTED TO NON-HOMEWORK FORUM I'm stuck on substituting the following (where gamma is the specific heat ratio): W=(P1v1 - P2v2) / (gamma-1) P1v1^gamma = P2v2^gamma substituting for v2... <= this is where I get stuck... W = [(P1v1) / (gamma-1)] * [(P2 /...

Homework Statement In the year 2004 the USA produced 1787 TWh of electrical energy in conventional thermal plants and 476 TWh in nuclear plants. Assuming 30% efficiency for nuclear plants and 40% for conventional thermal plants, determine the (annual) volume of cooling water required to cool...

Homework Statement Please consider a mixture of oxygen (1 mole), nitrogen (4 mole), and carbon dioxide (3 mole). The mixture was heated in a well - insulated vessel with 753 kJ. Determine the final temperature if the mixture is composed of real gases behaving ideally as described by Eq. 3.48...

Homework Statement Imagine I have a 3.5 kg brick at 80 °C that I put in 10l of water at 20 °C. What will the final temperature of the water be? SHC brick = 840 J kg-1 °C -1 Homework Equations E = mc∆θ The Attempt at a Solution First I calculated the energy available from the brick to heat...

Homework Statement A 1.0kg of ice at 0◦C, 3.0kg of water at 0◦C, and 5.0kg of iron at temperature T are placed in a sealed and insulated container. cFe =400J/ kg◦C ,cWater=4200J/ kg◦C , cIce= 2000 J/ kg◦C latent heat for ice is 3.3×105 J . The equilibrium temperature is 20◦C.Homework...

Homework Statement I'm asked to find the specific heat of Metal X in this simulation: http://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/thermochem/heat_metal.html Mass of Metal X = 120 g Temp of Metal X = 220 degrees Mass of Water = 30 g Initial Temp of Water = 20...

I have been trying to determine the efficiency of an ideal Otto cycle based on the compression ratio of my car and the heat of combustion of gasoline and I think I'm not entierly wrong but there is something quite off. When trying to calculate the temperature of the combustion stage my result...

I am doing some multi-fluid hydrodynamic modelling and I have a quick question. I think I know the answer, but I am not convinced. One of the things that I need to know is the specific heat ratio, ##\gamma##, for the gas and my question is, how does one calculate this from the values of each...

So I'm looking to calculate the time required to raise the temperature of a piece of lead. What I know so far: Mass of metal: 4 grams Initial temperature: 250 degrees Celsius Final temperature: 350 degrees Celsius Specific heat of lead: 0.13 kj/kg I'm very new to thermodynamics and don't know if...

Homework Statement Hi, I have an assignment to determine the specific heat capacity of water using a calorimeter, voltmeter and ammeter, where we connected the calorimeter to a 10V power pack and measured the temp of the water and the readings on the voltmeter and ammeter every minute. I ended...

Homework Statement There is a cylinder of oxygen connected to a valve (A) and then to connected to a regulatory valve. The volume of both valves and the pipes between them is Vr and can be disconsidered in regard to the cylinder's volume. The oxygen can be considered a perfect gas with...

Homework Statement Using equipartition law, find specific heat of gas containing triatomic linear molecules. Will the result be different if the molecule was non- linear? In what way? Homework Equations According to equipartion theorem, each degree of freedom gets (1/2)kT kinetic energy and...

I have uploaded a page from my prof's lecture on specific heat. Its given that average energy for each vibrational mode is $$\frac{h\nu}{e^{\frac{h\nu}{T}}-1}$$ Hence $$U=(\text{number of vibrational modes)}\times\frac{h\nu}{e^{\frac{h\nu}{T}}-1}$$ In the lecture slide, the number of...

I am trying to estimate the amount of electrical power needed to heat up a material from 20C to 1000C in 20 seconds. Assuming it is 18sqin and 3mm thick, I used the specific heat which was given as 0.78 J/gC and weight 11.39g (from the destiny of 3.26). 0.78 J/gC x 11.39g x (1000C - 20C) /...

Hello. I am doing a research paper on the relationship of specific heat capacity and refractive index of liquids. I am doing this by finding the relationship between specific heat capacity and concentration and refractive index and concentration. With this I can find a general trend and conclude...

so for one of my assignments i need to make a calculation which involves the mixture to be made of different types of substance... the heat capacity for each of the different unknown substances that were given: substance 1 = 1250J/kg °C substance 2 = 1130J/kg °C substance 3= 4100J/kg °C i need...

I'm a design draftsman, I have bar of 17-4 stainless steel it weighs 6.9 lbs. The Product Data Sheet shows a specific heat 0.11 (BTU/lb/F (32-212F) (www.aksteel.com) It's at room temperature or 70 degrees F. I want to cool the bar to 50 degrees F. The surface area of the bar is 245 sq. inches...

Homework Statement I know that for constant volume ∂q=du and so du=Cv.dT However i don't understand how did we get to ∂q=du by neglecting the vdP term of enthalpy What I am trying to say is, is enthalpy this ∆U+P∂V+V∂P or this ∆U+P∂V? I don't understand since the definition of enthalpy is...

Homework Statement In each of the following, state and explain which container will have the hotter liquid after thirty seconds: a) You pour equal amounts of of hot coffee into two cup s from a percolator. The cups are the same general size and shape. One is made from heavy china one is made...

[Mentor's note: this was originally posted in a non-homework forum and therefore does not use the homework template.] Hi everyone, I'm a bit stuck on this question and hoping someone could give me the solution. "A lump of lead, moving with a velocity of 22.0 m/s, is brought to rest. If 55.0%...

Homework Statement Suppose we drop a lead ball of mass M into water of mass m from a height h and allow everything to settle down. What is the temperature change of the water? Assume that the container is well insulated. Homework Equations Potential Energy = mgh dU = mcdT where dU is the...

Homework Statement My answer is question 3 part c the graph. SHC = c http://www.ocr.org.uk/Images/61757-question-paper-unit-g484-the-Newtonian-world.pdf [See page 7]Homework Equations E=mcdelta theta Power=Energy/Time Therfroe Power*Time = Mass*c*delta theta. The Attempt at a Solution See in...

Homework Statement An insulated beaker with neglible mass contains .3kg of water at a temp of 78.6 C. How many kg of ice at -19.6 C must be dropped into the water to make Tf= 22.7C? Specific heat for water= 4190 J/kgK specific heat for ice= 2100 J/kgK heat of fusion for water= 334kJ/kg...

I am studying for a thermo exam, and one of the problems I am doing deals with adiabatic expansion of a piston in a cylinder. When solving for work, the solution guide uses m*Cv*(T2-T1). I don't understand why they know how to use Cv instead of Cp. The pressure changes, so obviously you wouldn't...

Homework Statement The specific heat capacity of a metal at low temperature (T) is given as ##C_p = 32\left({\dfrac{T}{400}}\right)^3## (kJK-1kg-1). A 100g vessel of this metal is to be cooled from 20 K to 4 K by a special refrigerator operating at room temperature (27°C). The amount of work...

Hi, Say we have fluid A with thermal capacity C_a and fluid B with C_b. If we create a solution with X% of fluid A and (1-X)% of fluid B, is it true that the new thermal capacity of the mixture will be C_new ?= C_a*X + C_b * (1-X) Or it is a case-by-case relationship that depends on the nature...

It's possible to calculate the latent heats of fusion and the specific heat of a solution of H2O and NaCl? In some cases, it would have two latent heats of fusion? For example, at 10% NaCl, one at -21ºC and another at -5ºC? Thanks!

Homework Statement I had a lab where we put 50 grams of a metal smaple into a little bowl and then heated it with steam from a big beaker thing. Anyway, my question is about the errors I got in this lab when finding the specific heat of the metal. I had some high percent errors for Aluminum...

Homework Statement A copper container (mass: 100 g) holds 200 g of water. The temperature of the container and water is 20°C. A 150-g piece of copper heated to 80°C is placed in the water. The water is stirred thoroughly. After sufficient time elapses, to what temperature does the water change...

Homework Statement If a metal is highly susceptible to oxidation, what effect might this have on calculating the quantity of heat transferred to a metal? Use specific examples. Homework Equations Q=mcΔT The Attempt at a Solution Would oxidation change the specific heat of the metal? Since...

Equations: E=m*c* dTheta or T Experiment: I had two beakers of water with one thermometer in each beaker. One beaker had boiling water and the other beaker had room temperature water. I also had a 100g mass. I recorded T1 which was the intial temperature of the cold water. I then put the mass...

Homework Statement Does the specific heat of an ideal gas depend on the temperature only or does it depend on molecular weight and structure ? or both ? Homework Equations PV=mRT , Cp -Cv=R The Attempt at a Solution One of my teachers said it depends only on temperature and the other said...

So I have a question regarding the specific heat capacities in thermodynamics. In general the specific heat capacities for a gas (or gas mixture in thermo-chemical equilibrium) can be expressed as, ## c_p = \left(\frac{\partial h}{\partial T}\right)_p \qquad \text{and} \qquad c_v=...

I've read in my texts that the there are two kinds of Molar Specific Heat Capacities for gases: 1. Molar Specific Heat Capacity at constant Volume ----- ##C_v## 2. Molar Specific Heat Capacity at constant Pressure ---- ##C_p## And in case of Constant temperature there is no point in...

Homework Statement For my physics IA, I am finding the specific heat capacity of water-solute mixtures and finding how the specific heat differs from that of just water alone. I have the mass of the mixture, for example baking soda and water was 914.75g and changed 175.8 degrees Fahrenheit in...

Homework Statement Analyze the specific heat of a one dimensional lattice of identical atoms: Show within Debye approximation that the specific heat at low temperatures ( ≪ Θ) is proportional to T/ΘD . Here ΘD=ℏD/ kB = ℏvs/KBa is the Debye temperature valid for 1D, kB the Boltzmann...

I had an experiment to find the specific heat capacity of water. Materials are electric kettle, logger pro, 1 kg water, and set up the time to 240 seconds. The experiment value i got is 4.33 kJ/(kg.K) which is closed to the waters specific heat capacity 4,18 kJ/(kg.K). I wonder what could be...

Homework Statement Assuming no heat loss to the container or the environment, what is the final temperature (K) of a mixture of 9.28L of liquid 1 (density=1070kg/L & specific heat capacity of 4358J/kg/K) at 378K and 12.15L of a second liquid (density=1070kg/L & specific heat capacity of...

1. Homework Statement A gas (treated as air) powered turbine provides power to a compressor which then sends the compressed air through an intercooler (heat exchanger). Turbine: Gas enters @ 0.03kg/s, 370 degrees Celsius Gas leaves @ 300 degrees Celsius and a "lower pressure" Compressor...

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...

Hello, this is one of the problems in my laboratory manual and it has been killing me. I've been working on this all week. It's due tonight, so hopefully it's not too late... 1. Homework Statement Explain why specific heat is "specific", and how it gives a relative indication of molecular...

Homework Statement Wet clothing at 0°C is hung out to dry when the air temperature is 0°C and there is a dry wind blowing. After some time, it is found that some of the water has evaporated and the remainder has frozen. Estimate the fraction of the water originally present in the clothing which...

Homework Statement We have a sensor onboard a satellite that is faced towards Earth, from the Sun. The LW absorptivity is 0.8 (a_LW) and SW is 0.2 (a_SW). I need to find a equation for the temperature as a function of time. Given datas is the Area=0.3 m^2 and Specific Heat of 4 J/K Homework...

please help :( I know the formula, but i don't understand the question1. Homework Statement a 200g calorimeter, with heat capacity = 0.10 cal/g C, contains 300g of water. a 500 g aluminum shot, at 99 Celsius, was poured in the calorimeter. What would be the initial temperature of water in order...

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...

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...

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...