The space shuttle environmental control system handles excess CO2 (it is 4.0% by mass of exhaled air) by reacting it with LiOH, pellets to form Li2CO3 and water. If there are 7 astronauts on board ad each exhales 20.L of air per minute, how long could clean air be generated if there were 25,000g of LiOH pellets available. Assume the density of air is 0.0010g/ml.