I can't figure this out, can someone help me?

The density of an unknown gas at 98°c and 740 mmhg is 2.50 g/l. what is the molar mass of the gas with work showed?

Will give brainliest it is a lab from k12 here is the linkfor each metal that participated in a chemical change, write the type of metal it is, based on your examination of the periodic table. type your answer here. (score for question 3: of 5 points) were there any metallic compounds that did not react with either the acid or the base? write the type of metal, based on your examination of the periodic table. type your answer here. (score for question 4: of 5 points) make a general statement about the reactivity of the metals in this experiment. type your answer here.

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