(2012?徐汇区二模)化学反应N2+3H2→2NH3的能量变化如图所示,该反应的热化学方程式是( )A.N2(g
(2012?徐汇区二模)化学反应N2+3H2→2NH3的能量变化如图所示,该反应的热化学方程式是()A.N2(g)+H2(g)→NH3(1)-46kJB.N2(g)+H2...
(2012?徐汇区二模)化学反应N2+3H2→2NH3的能量变化如图所示,该反应的热化学方程式是( )A.N2(g)+H2(g)→NH3(1)-46 kJB.N2(g)+H2(g)→NH3(g)-454 kJC.N2(g)+3 H2(g)→2 NH3(g)+92 kJD.N2(g)+3 H2(g)→2 NH3(1)+431.3 kJ
展开
1个回答
展开全部
由图可以看出,
molN2(g)+
molH2(g)断键吸收的能量为204kJ,形成1molNH3(g)的放出的能量为250kJ,所以
N2(g)+
H2(g)=NH3(g)△H=-46kJ/mol,
而1mol的NH3(g)转化为1mol的NH3(l)放出的热量为22.7kJ,
根据盖斯定律可知:
N2(g)+
H2(g)=NH3(l)△H=-68.7kJ/mol,
即:N2(g)+3H2(g)=2NH3(g)△H=-92kJ/mol,N2(g)+3H2(g)=2NH3(l)△H=-137.4kJ/mol,
故选C.
1 |
2 |
3 |
2 |
1 |
2 |
3 |
2 |
而1mol的NH3(g)转化为1mol的NH3(l)放出的热量为22.7kJ,
根据盖斯定律可知:
1 |
2 |
3 |
2 |
即:N2(g)+3H2(g)=2NH3(g)△H=-92kJ/mol,N2(g)+3H2(g)=2NH3(l)△H=-137.4kJ/mol,
故选C.
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询