# gas law_F6 CHEM 問題

Rating

3.

(b)

Pressure on sea level

= 1 atm

Pressure at the seabed

= 1 + 1 x (20/10)

= 3 atm

(c)(i)

Consider the gas in the cylinder on the sea level:

Volume, V1 = 0.02 m3

Pressure, P1 = 18 atm

Temperature, T1 = 273 + 27 = 300 K

Consider the gas in the cylinder at the seabed just before the diver inflates the balloon:

Volume, V2 = 0.02 m3 (unchanged)

Pressure, P2 = ?

Temperature, T2 = 273 + 21 = 294 K

PV = nRT

P/T = nR/V

Since n, R and V are constant, thus P/T = constant

P1/T1 = P2/T2

18/300 = P2/294

Gas pressure in the cylinder just before the diver inflates the balloon, P2

= 294 x (18/300)

= 17.64 atm

(c)(ii)

Consider the gas originally in the cylinder used to inflate the balloon:

Volume, V3 = 0.02 m3

Partial pressure, P3 = ? atm

Temperature, T = 294 K

Consider the gas in the inflated balloon:

Volume, V4 = 0.01 m3

Pressure, P4 = 3 atm

Temperature, T = 294 K (unchanged)

PV = nRT

Since n, R and T are constant, thus PV = constant

P3V3 = P4V4

P3 x 0.02 = 3 x 0.01

P3 = 1.5 atm

Gas pressure in the cylinder just before the diver inflates the balloon

= 17.64 - 1.5

= 16.14 atm

c(iii)

According to Dalton's law of partial pressure,

fraction of the gas originally in the cylinder used to inflate the balloon

= 1.5/17.64

= 0.085