Ethylene, C2H4, is used to make plastic milk bottles. When the volume of 1000 g of ethylene at 25oC is decreased from 40.0 L to 15.0 L, what is the new temperature assuming the pressure is held constant?

The new temperature will be -161.25°C

Explanation:

To calculate the final temperature of the system, we use the equation given by Charles' Law. This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure.

Mathematically,

where,

are the initial volume and temperature of the gas.

are the final volume and temperature of the gas.

We are given:

Putting values in above equation, we get:

Converting the temperature from kelvins to degree Celsius, by using the conversion factor:

Hence, the new temperature will be -161.25°C

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