neon 2.5 cm 5.5 m 35℃ 1.78 torr gram πr2h

neon 2.5 cm 5.5 m 35℃ 1.78 torr gram πr2h

 

 

A neon sign is made of glass tubing

whose inside diameter is 2.5 cm and whose length is 5.5 m.

If the sign contains neon at a pressure of 1.78 torr at 35℃,

how many grams of neon are in the sign?

(The volume of a cylinder is πr2h.)

 

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V = πr^2h

= (3.14159) (2.5/2 cm)^2 (550 cm)

= 2699.8 cm^3

= 2699.8 mL

= 2.7 L

 

 

 

PV = nRT

( 참고 https://ywpop.tistory.com/3097 )

 

n = PV / RT

= [(1.78/760) (2.7)] / [(0.08206) (273.15 + 35)]

= 0.00025 mol Ne

 

 

 

Ne의 몰질량 = 20.18 g/mol

0.00025 mol × (20.18 g/mol) = 0.005045 g Ne

( 참고 https://ywpop.tistory.com/7738 )

 

 

 

답: 5.0×10^(-3) g