A mixture of gases with a pressure of 900 mm Hg contains 20% of oxygen and 80% of nitrogen by volumeWhat is the partial pressure of the oxygen gas in the mixture? A-45mmHg
B-180mmHg
C-210 mmHg
D-320 mmHg

180 mmHg

Explanation:

Total volume of gases = 20% + 80%= 100%

Total pressure of gases = 900 mm Hg

Note that partial pressure of a gas = mole fraction × total pressure

Mole fraction of oxygen = 20/100

Hence partial pressure of oxygen= 20/100 × 900 mm Hg

partial pressure of oxygen= 180 mmHg

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j