# Could anyone help me with parts B, C, and E it would be greatly appreciated?

Jun 6, 2018

$\text{B.}$

20% of air consist of oxygen.

So, mass of air that contains $\text{2.5 kg}$ oxygen is

$\text{m" = "2.5 kg"/(20%) = "2.5 kg"/20 × 100 = "12.5 kg}$

—————

$\text{C.}$

$\text{V"_"air" = "Mass"_"air"/"Density"_"air}$

color(white)("V"_"air") = "12.5 kg"/"1.29 kg/m"^3

color(white)("V"_"air") = "9.69 m"^3

—————

$\text{E.}$

"Use Volume of oxygen from part B"
There is no mention of volume of oxygen in part B

If $\text{12.5 kg}$ air whose volume is ${\text{9.69 m}}^{3}$ (calculated in part C) is stored in cylinderical tank then height ($h$) of the cylinder is

Volume of cylinder$=$ Volume of air$= \pi {r}^{2} h$

h = "V"_"air"/(πr^2)

color(white)(h) = "9.69 m"^3/(3.14 × ("1.85 m")^2)

$\textcolor{w h i t e}{h} = \text{0.902 m}$