I think you forgot to give the options along with the question. I am answering the question based on my research and knowledge. "<span>You should remove heat energy because air is a gas and particles need to slow to become a liquid" is the way you can make water for drinking in the desert. I hope it helped you.</span>
Answer : The correct option is, (B) ![CO_2](https://tex.z-dn.net/?f=CO_2)
Solution :
According to the Graham's law, the rate of effusion of gas is inversely proportional to the square root of the molar mass of gas.
![R\propto \sqrt{\frac{1}{M}}](https://tex.z-dn.net/?f=R%5Cpropto%20%5Csqrt%7B%5Cfrac%7B1%7D%7BM%7D%7D)
or,
..........(1)
where,
= rate of effusion of unknown gas = ![11.9\text{ mL }min^{-1}](https://tex.z-dn.net/?f=11.9%5Ctext%7B%20mL%20%7Dmin%5E%7B-1%7D)
= rate of effusion of oxygen gas = ![14.0\text{ mL }min^{-1}](https://tex.z-dn.net/?f=14.0%5Ctext%7B%20mL%20%7Dmin%5E%7B-1%7D)
= molar mass of unknown gas = ?
= molar mass of oxygen gas = 32 g/mole
Now put all the given values in the above formula 1, we get:
![(\frac{11.9\text{ mL }min^{-1}}{14.0\text{ mL }min^{-1}})=\sqrt{\frac{32g/mole}{M_1}}](https://tex.z-dn.net/?f=%28%5Cfrac%7B11.9%5Ctext%7B%20mL%20%7Dmin%5E%7B-1%7D%7D%7B14.0%5Ctext%7B%20mL%20%7Dmin%5E%7B-1%7D%7D%29%3D%5Csqrt%7B%5Cfrac%7B32g%2Fmole%7D%7BM_1%7D%7D)
![M_1=44.2g/mole](https://tex.z-dn.net/?f=M_1%3D44.2g%2Fmole)
The unknown gas could be carbon dioxide
that has approximately 44 g/mole of molar mass.
Thus, the unknown gas could be carbon dioxide ![(CO_2)](https://tex.z-dn.net/?f=%28CO_2%29)