I do not have any definition. It is said in the task. I guess it means, there is nothing influencing the expansion of gas.Chestermiller said:What is your definition of free expansion conditions?
Usually, free expansion is defined as expansion into a vacuum. However, I don't think that is what was intended here. I think what was intended here is expansion against a constant pressure equal to the initial pressure of the gas. If that were the case, then the amount of heat supplied would be equal to the change in enthalpy of the gas. This is given by $$Q=\Delta H=nC_p\Delta T$$where n is the number of moles and ##C_p## is the molar heat capacity of the gas. Are you given no information about the gas? If not, from the answer they gave, what is the molar heat capacity of the gas?MisterP said:I do not have any definition. It is said in the task. I guess it means, there is nothing influencing the expansion of gas.
There is nothing more.. Just the temperature - 100K (how much it was risen) and 1kmole, that`s it.. Maybe the fact that it is multi-atom gas changes something?Chestermiller said:If not, from the answer they gave, what is the molar heat capacity of the gas?
Not really. What do you calculate for Cp? That might tell us something.MisterP said:There is nothing more.. Just the temperature - 100K (how much it was risen) and 1kmole, that`s it.. Maybe the fact that it is multi-atom gas changes something?
Let's see the number you get using their answer.MisterP said:I really do not know.. :(
Edit: or c = Q / (mΔT). ??
But that won`t help..
Dues the equation I wrote make sense to you? What course is this for?MisterP said:I do not get it. I have not been solving these types of tasks since I was in high school, that's around 13 years ago and now they through all the themes on basic physics and I have to solve this "easily" they say ..
We are trying to "back out" the value of Cp from the answer they gave to see if we can make any sense out of it.MisterP said:We had 3 day course on physics - starting mechanics, energy, oscilations, molecular physics, thermodynamics, electrics. I am studying electric engeneering and so, there is this fast course on physics, just for a check. I do understand Your formula, but I do not have Cp.
Very nice.MisterP said:So, I found this. E = x*n*R*T
If x = 4, then I get right answer, but I do not know if this is right. But I have seen that x is 3.
n - moles
R - 8.3 constant
T - temperature
Edit: x = i/2+1
i = 6 for multi atomic gases, so that is how to get 4 and seems like this formula works :)
The amount of heat supplied to a gas can be calculated using the formula Q = mcΔT, where Q is the amount of heat supplied, m is the mass of the gas, c is the specific heat capacity of the gas, and ΔT is the change in temperature.
The specific heat capacity of a gas is the amount of heat required to raise the temperature of one unit mass of the gas by one degree Celsius.
The mass of a gas can be determined by using a scale or by measuring the volume of the gas and using the ideal gas law equation, PV = nRT, where P is the pressure of the gas, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.
The units for specific heat capacity are typically Joules per kilogram per Kelvin (J/kg/K). Temperature can be measured in Kelvin (K) or degrees Celsius (°C).
Yes, this formula can be used for all types of gases as long as the specific heat capacity is known. However, for gases that undergo phase changes, such as water vapor, an additional term may need to be added to the formula to account for the heat of vaporization or condensation.