Answer:
η = 0.5686
Explanation:
Isentropic compressor efficiency (η):
* η = Isentropic compressor work / real compressor work = Ws / Wreal
∴ Wreal = 76 KW = 76 KJ/s
first law:
∴ Q = 0 ....adiabatic compressor
∴ ΔU = CvΔT
∴ W = - PδV
⇒ ΔU = W ,,,,,isentropic process adiabatic
⇒ CvΔT = - PδV
ideal gas:
⇒ (R + Cv / R) Ln(T2/T1) = Ln (P2/P1)
∴ Cv = 3/2 R....monoatomic ideal gas
∴ R = 8.314 E-3 KJ/K.mol
∴ P1 = 90 KPa
∴ P2 = 800 KPa
∴ T1 = 25 °C ≅ 298 K
∴ r He = 2 Kg/min
⇒ (5/2) Ln(T2/T1) = Ln(800/90) = 2.185
⇒ Ln (T2/T1) = 0.874
⇒ T2/T1 = e∧0.874 = 2.3963
⇒ T2 = (2.3963)(298 K) = 714.094 K
⇒ Ws = CvΔT = (3/2 R)(714.094 - 298 ) = 5.1891 KJ/mol
∴ Mw He = 4.0026 g/mol
⇒ Ws = ( 5.1891 KJ/mol)(mol / 4.0026 g)(1000 g/Kg)(2Kg/min)(min/60s)
⇒ Ws = 43.2144 KJ/s
⇒ η = 43.2144 KJ/s / 76 KJ/s = 0.5686
A mole of any element is equal to avogadro's number which is equivalent to 6.0221409e+23, that is 6.0221409e+23 molecules or atoms per mole.In this case, we are given with 9.87 sample which when multiplied to Avogadro's number is equal to <span>5.943853e+24 atoms.</span>
Answer: Solid, Liquids, Plasma. Gas.
Explanation:
It retains its shape regardless of the shape of the container----- Solid
Particles move freely but do not separate from neighboring particles---- Liquids
This state, in which the particles are at extremely high temperatures, is rarely found on Earth---- Plasma
It expands to fill the volume of the container.------- Gas
There are four states of matter, of which the common ones are
Gases- whose particles are compressible and takes the shape and volume of its container
, Liquids - whose particles freely slide over each other and assumes the shape of the part of the container which they occupy and
Solids whose particles are rigid and maintain thier fixed volume and shape regardless of the container they are put .
The last one is the Plasma, a rare state of matter not common to earth nwhose particles are so hot that they exist around the sun, stars and outer space.
Answer: 1.5 moles O2
Explanation:
The number of moles of each reactant and product is the number in front to the molecule when the equation is balanced.
You know that 1 mole of O2 gives you 2 moles of H2O
So you can set up a proportion using that.
1 mole O2. X moles O2
-------------- = -------------------
2 moles H2O. 3 moles H2O
Then cross multiply
2x=3
X=3/2 Or 1.5
So you need 1.5 moles O2 to get 3 moles of H2O.
The balance chemical reaction describing the reaction between Mg2+ and Cl- is shown below,
Mg2+ + 2Cl- ----> MgCl2
This is a reaction where there is a transfer of electrons. Since the valence electron of Mg2+ is 2 and that of Cl- is only 1. There is a need for 2 Cl- to react with 1 Mg2+ in order to balance the equation.
Thus, the anwer is MgCl2.