The full question asks to decide whether the gas was a specific gas. That part is missing in your question. You need to decide whether the gas in the flask is pure helium.
To decide it you can find the molar mass of the gas in the flask, using the ideal gas equation pV = nRT, and then compare with the molar mass of the He.
From pV = nRT you can find n, after that using the mass of gass in the flask you use MM = mass/moles.
1) From pV = nRT, n = pV / RT
Data:
V = 118 ml = 0.118 liter
R = 0.082 atm*liter/mol*K
p = 768 torr * 1 atm / 760 torr = 1.0105 atm
T = 35 + 273.15 = 308.15 K
n = 1.015 atm * 0.118 liter / [ 0.082 atm*liter/K*mol * 308.15K] =0.00472 mol
mass of gas = mass of the fask with the gas - mass of the flasl evacuated = 97.171 g - 97.129 g = 0.042
=> MM = mass/n = 0.042 / 0.00472 = 8.90 g/mol
Now from a periodic table or a table you get that the molar mass of He is 4g/mol
So the numbers say that this gas is not pure helium , because its molar mass is more than double of the molar mass of helium gas.
Answer:
A. The rate of heat transfer through the material would increase.
Explanation:
To calculate the heat transfer in a heat exchanger you decide that there is not heat leakage to the surroundings, that means that magnitude of the two transfer rates will be equal. Any heat lost by the hot fluid, is gained by the cold fluid. The equation that describes this is Q = m×Cp×dT
Where:
heat = mass flow ×specific heat capacity × temperature difference
So if we increase the rate of flow of cooling water and the other variables that ypu can control remain the same, the result is that the rate of heat transfer through the material would increase, as it is stated in option a.
In ferromagnetic materials, smaller groups of atoms band together into areas called domains, in which all the electrons have the same magnetic orientation. That's why you can magnetize them. See how it works in this tutorial.
Answer:
I believe it's 4892,08808J
Explanation:
∆T=158,8g•4,18÷g°C•7,37°C
=4'892,08808J
