A:2C2H2(g)+5O2(g)=4CO2(g)+2H2O(l);ΔH=-2b kJ • mol-1
B:C2H2(g)+5/2O2(g)=2CO2(g)+H2O(l);ΔH=2b kJ • mol-1
C:2C2H2(g)+5O2(g)=4CO2(g)+2H2O(l);ΔH=-4b kJ • mol-1
D:2C2H2(g)+5O2(g)=4CO2(g)+2H2O(l);ΔH=b kJ • mol-1
为了迎接上海世博会,组委会向社会招募了大量懂英语的志愿者,因为英语是( )
—How do you spend the coming May Day holiday?— I haven't decided. I wonder during the holiday.
— Can I join the English club?
— Sure. Please show ______ your school ID card.
对于0.1mol/LNa2SO3溶液,正确的是( )