1. Explain what is meant by atmospheric, prompt, and fuel NO.

2. Does prompt NO form in carbon monoxide−air flames? Why or why not?

3. Which is most sensitive to temperature—the formation of atmospheric, prompt, or fuel NO?

4. Order the tendency to soot of the following fuels under premixed combustion with air: hexadecane, ethyl benzene, cycloheptane, heptane, and heptene.

5. New freon agent compounds containing only fluorine atoms are being considered because fluorine atoms do not disturb the ozone layer in the manner as chlorine atoms. Can you explain why?

6. Order the following compounds in their tendency to soot under diffusion flame conditions: vinyl acetylene, ethene, phenyl acetylene, benzene, and acetylene.