Answer to Question #280055 in Inorganic Chemistry for Poly

Question

A helium gas cylinder of the sort used to fill balloons has a volume of 180 L and and a pressure of 2200 psi ( 150 atm) at 25° C. How many moles of helium are in the tank? How many grams?

Answer 1

Given n

=

Mass

Molar mass

=

P

V

R

T

.

Mass

=

P

V

R

T

×

molar mass

,

.........Agreed........?

And, as is typical, we use the value of..........

R

=

0.0821

⋅

L

⋅

a

t

m

⋅

K

−

1

⋅

m

o

l

−

1

The which has units that chemists typically use. And so we plugs in the numbers:

Mass

=

1.2

⋅

a

t

m

×

2.00

⋅

L

×

4.00

⋅

g

⋅

m

o

l

−

1

0.0821

⋅

L

⋅

a

t

m

K

⋅

m

o

l

×

300

⋅

K

≅

400 moles