A sample of helium has a volume of 50.00 L at STP. How many helium atoms are in the sample? Show work

Explanation:

molar volume at STP=22.4 L

given volume=50.0 L

number of moles=given volume/molar volume

number of moles=50.0/22.4

number of moles=2.2

1 mole of helium =6.023*10^23 atoms

2.2 moles of helium =6.023*10^23*2.2=1.3*10^24

therefore 50.0 L of helium contain 1.33*10^24 atoms

calculate how many grams of ammonia can be produced from 4.21 grams of

n2 + 3h2 = 2nh3

my answer:

25.0g n2 x (1 mol/ 28.0gn2) x (2 mol nh3/ 1 mol n2) x (17.0g nh3/ 1 molnh3) = 30.36g n2

25.0g h2 x (1 mol h2/ 2.00g h2) x (2 mol nh3/ 3 mol h2) x (17.0g nh3/ 1 mol nh3) = 141.67g h2

lr = n2

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.