Determine el cambio en entalpia para el proceso 2B=C​

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

Can someone me with questions 12 and 13 plz.

22. a flask containing 450 ml of 0.50 m h2so4 was accidentally knocked to the floor. how many grams of nahco, do you need to put on the spill to neutralize the acid according to the following equation: h2so4(aq)+2 nahcos(aq) na,so(aq) +2 h20()+2 co2(g) d) 38 g a) 2.3 g b) 9.5 g c) 19 g