Answer:
- final temperature (T2) = 748.66 K
- ΔU = w = 5620.26 J
- ΔH = 9367.047 J
- q = 0
Explanation:
ideal gas:
reversible adiabatic compression:
∴ q = 0
∴ w = - PδV
⇒ δU = δw
⇒ CvδT = - PδV
ideal gas:
⇒ PδV + VδP = RδT
⇒ PδV = RδT - VδP = - CvδT
⇒ RδT - RTn/PδP = - CvδT
⇒ (R + Cv,m)∫δT/T = R∫δP/P
⇒ [(R + Cv,m)/R] Ln (T2/T1) = Ln (P2/P1) = Ln (1 E6/1 E5) = 2.303
∴ (R + Cv,m)/R = (R + (3/2)R)/R = 5/2R/R = 2.5
⇒ Ln(T2/T1) = 2.303 / 2.5 = 0.9212
⇒ T2/T1 = 2.512
∴ T1 = 298 K
⇒ T2 = (298 K)×(2.512)
⇒ T2 = 748.66 K
⇒ ΔU = Cv,mΔT
⇒ ΔU = (3/2)R(748.66 - 298)
∴ R = 8.314 J/K.mol
⇒ ΔU = 5620.26 J
⇒ w = 5620.26 J
⇒ ΔH = ΔU + nRΔT
⇒ ΔH = 5620.26 J + (1 mol)(8.314 J/K.mol)(450.66 K)
⇒ ΔH = 5620.26 J + 3746.787 J
⇒ ΔH = 9367.047 J
Answer:
Option B. +3 and +6
Explanation:
<em>Zeff</em> = <em>z - s</em>
where <em>z</em> is the atomic number, <em>s</em> is the number of shielding(non-valence) electrons
For Boron, electronic configuration is 1s²2s³.
z = 5, s = 2
Zeff = 5 - 2 = +3
For Oxygen, electronic configuration is 1s²2s²2p⁴
z = 8, s = 2
Zeff = 8 - 2 = +6
The top left corner shows the atomic number which is 3.
