Air is about 78% nitrogen gas (n2) by mass. The molar mass of nitrogen gas is 28. 0 g/mol. A 100. 0-g sample of air contains how many moles of nitrogen? 2. 8 3. 6 28 78.

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Two technicians are discussing how to test a car's exhaust by holding a small piece of paper within an inch of the tailpipe mouth. technician a says that if the paper is vibrating due to a "puffing" output from the tailpipe, this signals a smoothly running engine. technician b says that if the paper is being drawn toward the tailpipe, this could indicate burned exhaust valves. who is correct? a. technician b b. both technicians a and b c. technician a d. neither technicians a or b

Whats begin with t, ends with t has t in it