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选择题 已知下列热化学方程式:
(1)CH3COOH(l)+2O2(g) ="==" 2CO2(g)+2H2O(l)???? △H1= -870.3 kJ·mol-1
(2)C(s)+O2(g) ="==" CO2(g)?????????????????????△H2= -393.5 kJ·mol-1
(3)H2(g)+O2(g) ="==?" H2O(l)???????????????????△H 91exam.org3= -285.8 kJ·mol-1
则反应2C(s)+2H2(g)+O2(g)===CH3COOH(l) 的焓变△H为kJ·mol-1
A.488.3
B.-244.15
C.244.15
D.-488.3
选择题 已知下列热化学方程式:
(1)CH3COOH(l)+2O2(g) ="==" 2CO2(g)+2H2O(l)???? △H1= -870.3 kJ·mol-1
(2)C(s)+O2(g) ="==" CO2(g)?????????????????????△H2= -393.5 kJ·mol-1
(3)H2(g)+O2(g) ="==?" H2O(l)???????????????????△H3= -285.8 kJ·mol-1
则反应2C(s)+2H2(g)+O2(g)===CH3COOH(l) 的焓变△H为kJ·mol-1
A.488.3
B.-244.15
C.244.15
D.-488.3
本题答案:D
本题解析:(2)×2 +(3)×2-(1)得2C(s)+2H2(g)+O2(g)===CH3COOH(l)
2△H2+2△H3 —△H1=(-393.5 kJ·mol-1)×2+(-285.8 kJ·mol-1)×2-
(-870.3 kJ·mol-1)=-488.3 kJ·mol-1
本题所属考点:【金属及其化合物】
本题难易程度:【简单】
If thou dealest with a fox, think of his tricks. 与狐狸周旋,要谨防上当。