Select all the exothermic reactions from the list below. Group of answer choices

C + O2 --> CO2 + 167 kJ

KClO3 + heat --> KCl + O2

2Al + Fe2O3 --> Al2O3 + 2Fe + heat

2Zn(NO3)2 + heat --> 2ZnO + 2NO2 + 3O2

2H2O2 --> 2H2O + O2 + 148 kJ

If 0.414 g of hydrogen is obtained in this experiment how many grams of sulfur must be obtained

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange