Corrosion inside a closed container can result in an oxygen-deficient atmosphere within the container. the typical corrosion rate for carbon steel in very moist air is about 0.127 mm/yr and is approximately first-order with respect to the oxygen concentration. assuming that the corrosion reaction can be approximated by the reaction 3 2fe o2 fe2o3 determine the exposure time required to reduce the oxygen content in a closed 7.6-m-diameter spherical container from 21 to 19.5 mol %

Air pressure is measured in pascals. for a professional american football game, the ball should be inflated to about 90,000 pascals. scientists studied the effects of air temperature on the pressure inside american footballs by taking these steps: 1. prepare 100 footballs. 2. measure each football's air pressure. 3. divide footballs into 10 groups. 4. place the groups in different lockers cooled to different air temperatures. 5. after 12 hours, remove the footballs from lockers. 6. measure each football's pressure again. 7. compare the new pressures to the starting pressures. what two terms best describe the variable "air pressure inside the football" in this experiment? independent, qualitative independent, quantitative dependent, qualitative dependent, quantitative