Question

【题目】1mol氨气（化学式为：NH3）分解成氮气和氢气要吸收46.19kJ的热量，下列热化学方程式中正确的是（　　）

A.2NH3=N2+3H2-46.19kJ

B.2NH3(g)=N2(g)+3H2(g)-46.19kJ

C.NH3(g)=1/2N2(g)+3/2H2(g)-46.19kJ

D.2NH3(g)=N2(g)+3H2(g)+92.38kJ

Answer 1

【答案】C

【解析】

1mol NH3分解成氮气和氢气要吸收46.19kJ的热量，则热化学方程式为NH3(g)=1/2N2(g)+3/2H2(g) H= +46.19kJ或NH3(g)=1/2N2(g)+3/2H2(g)-46.19 kJ，故C正确；

故答案选C。