Question

The Saturn V was the most powerful rocket ever built and was central to the success of the Apollo program in the 1960s. The rocket used liquid oxygen (O2) as a component of its propellant systems in all three stages.
Consider a liquid oxygen (O2) tank within the rocket of volume 443968 L. How many molecules of O2 would be present in this tank? The density of liquid oxygen is 1.14 kg/L.

Express your answer to two significant figures.

Answer 1

Applying formula

$density=\frac{mass}{volume }$

$mass =1.14\times443968=506123.52 kg$$=506123520grams$

Let's calculate the moles of oxygen

no. of moles$=\frac{given\ mass }{molar\ mass }=\frac{506123520}{32}=15816360=1.58\times10^7 moles$

1 mole contains $6.023\times10^{23}$ molecules

$1.58\times10^7$ mole will contain $1.58\times10^7\times6.023\times10^{23} molecules =9.51\times10^{30}$ molecules