A
反应C(s,金刚石)+O 2(g)=CO 2(g) △H 1="-a" kJ/mol减去
C(s,石墨)+O 2(g)=CO 2(g)△H 2=-bkJ/mol
得到:C(s,金刚石)=C(s,石墨)△H=b-a=-1.9kJ/mol
即a>b,选A
A
反应C(s,金刚石)+O 2(g)=CO 2(g) △H 1="-a" kJ/mol减去
C(s,石墨)+O 2(g)=CO 2(g)△H 2=-bkJ/mol
得到:C(s,金刚石)=C(s,石墨)△H=b-a=-1.9kJ/mol
即a>b,选A