Nitric oxide gas, NO(g), can be oxidized in air to produce nitrogen dioxide gas, NO2(g):
2 NO(g) + O2(g) → 2 NO2(g)
Determine the enthalpy change for this reaction
using any of these thermochemical equations:
O2(g) → 20(g)
AH = +495 kJ
NO(g) + O2(g) → NO2(g) + O2(g) AH = -199 kJ
203(g) → 302(g)
AH = -427kJ

As a part of an experiment a student burns propane to produce carbon dioxide and water she remembers that she must follow the law conservation of matter when writing a balanced chemical equation which of these equation adheres to the law of conservation of matter

You exhale co2 which is produced during cellular respiration.  co2 combines with the water in your blood's plasma to make up one half of the body's most important buffer pair, carbonic acid.  the more physical activity you engage in, the more co2 your body is producing.  you can see this by putting some of the cabbage indicator in a glass and then blowing bubbles into it through a straw.  can you see a change in the color of the indicator?

Which of these are physical changes in matter? check all that apply boiling water a pencil being sharpened exploding dynamite freezing water rotting cheese