问题
选择题
已知298K时下述反应: ①C(s)+1/2O2(g)=CO(g)△H1=-110.5kJ•mol-1 ②CO(g)+1/2O2(g)=CO2(g)△H2=-283.0kJ•mol-1 ③C(s)+CO2(g)=2CO(g)△H3, 则△H3等于( ) A.172.5kJ•mol-1 B.-172.5kJ•mol-1 C.393.5kJ•mol-1 D.-393.5kJ•mol-1 |
答案
答案:A