What is the mass of 23450 L of hydrogen gas at STP

Remember that in this case pressure is equal to 1.00 atm and temperature is equal to 273.15K. So,

P

V

=

n

R

T

→

n

=

P

V

R

T

=

1.00

a

t

m

⋅

7.0

L

0.082

a

t

m

⋅

L

m

o

l

⋅

K

⋅

273.15

K

=

0.31

Since we know hydrogen's molar mass (

2.0

g

m

o

l

), we can determine the mass

m

H

2

=

n

⋅

m

o

l

a

r

.

m

a

s

s

=

0.31

m

o

l

e

s

⋅

2.0

g

m

o

l

=

0.62

g

If indeed you are dealing with STP, remember that, under these conditions, 1 mole of any ideal gas occupies

22.4

L

. So,

n

=

V

V

m

o

l

a

r

=

7.0

L

22.4

L

=

0.31

moles

And, once again,

m

=

0.31

⋅

2.0

=

0.6