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?
a 2.8
b 3.6
c 28
d 78

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.

May someone me with these science questions