What is the ph of a solution when the number of h+ ions equals the number of oh– ions in the liquid?

Can someone me with questions 15 to 17 plz.

Which suspect most likely committed the robbery and how do you know

Which formula equation represents the burning of sulfur to produce sulfur dioxide? s(s) + o2(g) 4502(9) 2h2s(s) + 302(g) —> 2h20(0) + 2502(9) 4fes2+1102 —> 2fe2o3 + 8502 2802(g) + o2(9) v205 , 2503(9)