Answer: The value of change in internal energy of the system is, 40 J.
Explanation : Given,
Heat absorb from the surroundings = 12 J
Work done on the system = 28 J
First law of thermodynamic : It is a law of conservation of energy in which the total mass and the energy of an isolated system remains constant.
As per first law of thermodynamic,
where,
= internal energy = ?
q = heat absorb from the surroundings
w = work done on the system
Now put all the given values in this formula, we get the change in internal energy of the system.
Therefore, the value of change in internal energy of the system is, 40J.
Just you think about it, a shower with hot water, you step out and it is cold, this happens because you have a enclosed space with the heat, so you get use to the heat, you step out it is cold. Hope this helped!
The molar mass of a, b and c at STP is calculated as below
At STP T is always= 273 Kelvin and ,P= 1.0 atm
by use of ideal gas equation that is PV =nRT
n(number of moles) = mass/molar mass therefore replace n in the ideal gas equation
that is Pv = (mass/molar mass)RT
multiply both side by molar mass and then divide by Pv to make molar mass the subject of the formula
that is molar mass = (mass x RT)/ PV
density is always = mass/volume
therefore by replacing mass/volume in the equation by density the equation
molar mass=( density xRT)/P where R = 0.082 L.atm/mol.K
the molar mass for a
= (1.25 g/l x0.082 L.atm/mol.k x273k)/1.0atm = 28g/mol
the molar mass of b
=(2.86g/l x0.082L.atm/mol.k x273 k) /1.0 atm = 64 g/mol
the molar mass of c
=0.714g/l x0.082 L.atm/mol.K x273 K) 1.0atm= 16 g/mol
therefore the
gas a is nitrogen N2 since 14 x2= 28 g/mol
gas b =SO2 since 32 +(16x2)= 64g/mol
gas c = methaneCH4 since 12+(1x4) = 16 g/mol
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