The answer is given, I'd like to know how to do it.

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.

How will the volume of a gas be affected if the pressure is tripled, but the temperature remains the same?