• 2021-04-14
    【单选题】已知1 A + B—→ C + D,△rHm,1=-40.0KJ·mol,22C + 2D—→ E, △rHm,2=60.0KJ·mol,则反应3E—→ 2A+2B的△rHm,3等于()
    A. 140KJ·mol+1 B. -140 KJ·mol+1 C. -20 KJ·mol+1 D. 20 KJ·mol
  • 20 KJ·mol

    内容

    • 0

      【单选题】已知反应: (1) CO(g) + H2O(g) = CO2(g) + H2(g) ,  (298K) = - 41.2 kJ/mol (2) CH4(g) + 2 H2O(g)= CO2(g) + 4 H2(g),  (298K) = 165.0 kJ/mol 则 CH4(g) + H2O(g) = CO(g) + 3 H2(g) 的 (298K) = 。 A. - 206.2 kJ/mol B. 123.8 kJ/mol C. 206.2 kJ/mol D. - 123.8 kJ/mol

    • 1

      已知MnO2 (s) = MnO (s) + 1/2 O2 (g) r HmΘ = 134.8 kJ∙mol−1,MnO2 (s) + Mn (s) = 2MnO (s) r HmΘ = -250.1 kJ∙mol−1,则MnO2的标准摩尔生成热f HmΘ为( ) A: -519.7 kJ∙mol−1 B: 519.7 kJ∙mol−1 C: 317.5 kJ∙mol−1 D: -317.5 kJ∙mol−1

    • 2

      已知H2O(g) = H2(g) +0.5O2(g),ΔrHm(1) = 241.8 kJ·mol–1;H2(g) = 2H(g),ΔHm(2) = 436.0 kJ·mol–1;0.5O2(g) = O(g),ΔHm(3)=247.7 kJ·mol–1则H2O中H–O键的平均键焓(单位:kJ·mol–1)为() A: 462.8 B: 925.5 C: –462.8 D: 241.8

    • 3

      已知反应B4C(s)()+4O2(g)()=2B2O3(s)()+CO2(g)的ΔrHmΘ=-2859()kJ·mol-1;而且ΔfHmΘ(B2O3)()=()-1273()kJ·mol-1;ΔfHmΘ(CO2)()=()-393()kJ·mol-1。则ΔfHmΘ(B4C)为()。A.()-()2859()kJ·mol()-()1B.()-()1666()kJ·mol()-()1C.()1666()kJ·mol()-()1D.()-()80.0()kJ·mol()-()1

    • 4

      已知C 2H 6(g)+7/2O 2(g) = 2CO 2(g) +3H 2O(l),C 2H 6(g)、CO 2(g)、H 2O(l)的Δ fH m y(kJ·mol -1)分别为:-85、-394、-286,试求上述反应的Δ rH m y为______。 A: -85+394+286(kJ·mol -1) B: -394+85-286(kJ·mol -1) C: -85-2×(-394)-3×(-286)(kJ·mol -1) D: 2×(-394)+3×(-286)-(-85)(kJ·mol -1)