What should be the mole fraction of $O_2$ in the gas mixture the diver breathes in order to have the same partial pressure of oxygen in his lungs as he would at sea level? Note that the mole fraction of oxygen at sea level is 0.209.

<u>Answer:</u> The mole fraction of oxygen in the gas mixture is 0.00573

<u>Explanation:</u>

To calculate the partial pressure, we use the equation given by Raoult's law, which is:

$p_{A}=p_T\times \chi_{A}$ ........(1)

where,

$p_A$ = partial pressure of oxygen at sea level = ?

$p_T$ = total pressure at sea level = 1.00 atm

$\chi_A$ = mole fraction of oxygen at sea level = 0.209

Putting values in equation 1, we get:

$p_{O_2}=1.00atm\times 0.209\\\\p_{O_2}=0.209atm$

As, partial pressure of the oxygen in the diver's lungs is equal to the partial pressure of oxygen at sea level

We are given:

$p_T=36.5atm\\p_{O_2}=0.209atm$

Putting values in equation 1, we get:

$0.209atm=36.5atm\times \chi_{O_2}\\\\\chi_{O_2}=\frac{0.209}{36.5}=0.00573$

Hence, the mole fraction of oxygen in the gas mixture is 0.00573

3 0

3 years ago

A solar heating specialist is considering paraffin (Cp = 2.90 J/g O C) as a storage material for heat. How many kg of paraffin w

Stels [109]

Answer:

Mass of paraffin that would be needed to collect the amount of energy as 4.73 x 10³ kg of water is 6.85 * 10³ kg

Explanation:

Specific heat capacity of paraffin, Cp = 2.90 J/g.°C = 2900 J/kg.°C

Specific heat capacity of water = 4.20 J/g.°C = 4200 J/kg.°C

Amount of heat energy that can be stored by 4.73 * 10³ kg of water heated through a degree rise in temperature can be calculated as below:

Using H = mCpθ where m is mass of substance, Cp is specific heat capacity and θ is temperature change

H = 4.73 * 10³ kg * 4200 J/kg.°C * 1°C

H = 19866000 J

Mass of paraffin that would be needed to collect the amount of energy as 4.73 x 10 3 kg of water for a degree rise in temperature is calculated as follows:

H = mCpθ

19866000J = m * 2900 J/kg.°C * 1°C

m = 19866000J / 2900 J/kg

m = 6850.34 kg = 6.85 * 10³ kg

Therefore, mass of paraffin that would be needed to collect the amount of energy as 4.73 x 10³ kg of water is 6.85 * 10³ kg

7 0

3 years ago