已知 (1)H2( g )+1/2O2 ( g ) = H2O ( g ) ΔH1 = a kJ/mol (2)2H2( g )+O2 ( g ) =2H2O ( g ) ΔH2 = b kJ/mol (3) H2( g )+1/2O2 ( g ) = H2O ( l ) ΔH3 = c kJ/mol (4) 2H2( g )+O2 ( g ) =2H2O ( l ) ΔH4 = d kJ/mol 则a.b.c.d的关系正确的是 A C . A.a<c<0 B.b>d>0 C.2a=b< 0 D.2c=d>0 查看更多

 

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已知
⑴ H2(g)+1/2O2(g)===H2O(g) ; △H1=a kJ·mol-1
⑵ 2H2(g)+ O2(g)===2H2O(g) ; △H2=b kJ·mol-1
⑶ H2(g)+1/2O2(g)===H2O(l) ; △H1=c kJ·mol-1
⑷ 2H2(g)+O2(g)===2H2O(l) ; △H2=d kJ·mol-1
下列关系式中正确的是
[     ]
A.a<b<0
B.b>d>0
C.2a=b<0
D.2c=d>0

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已知⑴H2(g)+ 1/2 O2(g)=H2O(g);   △H1=a  kJ/mol

⑵2H2(g)+ O2(g)=2H2O(g);    △H2=b  kJ/mol

⑶H2(g)+ 1/2O2(g)=H2O(l);    △H3=c  kJ/mol

⑷2H2(g)+ O2(g)=2H2O(l);     △H4=d  kJ/mol

下列关系式中正确的是(     )

A.a<c<0          B.b>d>0            C.2a=b<0            D.2c=d>0         

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已知下列热化学方程式:
(1)CH3COOH(l)+2O2(g)==2CO2(g)+2H2O(l) ΔH1=-870.3 kJ·mol-1
(2)C(s)+O2(g)===CO2(g)   ΔH2=-393.5 kJ·mol-1
(3)H2(g)+O2(g)===H2O(l)  ΔH3=-285.8 kJ·mol-1
则反应2C(s)+2H2(g)+O2(g)===CH3COOH(l)的焓变ΔH为

A.+ 488.3 kJ·mol-1      B.-244.15 kJ·mol-1
C.+ 244.15 kJ·mol-1D.-488.3 kJ·mol-1

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已知氢气和碳燃烧的热化学方程式为:

①2H2(g)+O2(g)=2H2O(l)    △H1=-akJ·mol1

②H2(g)+1/2O2(g)=H2O(g)   △H2=-bkJ·mol1

③C(s)+1/2O2(g)=CO(g)   △H3=-ckJ·mol1

④C(s)+O2(g)=CO2(g)   △H4=-dkJ·mol1  

下列说法错误的是

A.氢气的燃烧热为△H=-akJ·mol1                    B.c<d

C.一氧化碳的燃烧热为△H=-(d-c)kJ·mol1         D.0.5a>b

 

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已知下列热化学方程式:

(1)CH3COOH(l)+2O2(g)==2CO2(g)+2H2O(l) ΔH1=-870.3 kJ·mol-1

(2)C(s)+O2(g)===CO2(g)   ΔH2=-393.5 kJ·mol-1

(3)H2(g)+O2(g)===H2O(l)  ΔH3=-285.8 kJ·mol-1

则反应2C(s)+2H2(g)+O2(g)===CH3COOH(l)的焓变ΔH为

A.+ 488.3 kJ·mol-1              B.-244.15 kJ·mol-1

C.+ 244.15 kJ·mol-1                   D.-488.3 kJ·mol-1

 

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