What volume is occupied by 0.35 mol of helium gas at SATP?

1 Answer
Jul 18, 2017

"7.84 L"7.84 L

Explanation:

I will assume that you mean "STP (Standard Temperature and Pressure)"STP (Standard Temperature and Pressure).

Since we know that "1 mole"1 mole of an ideal gas occupies "22.4 L"22.4 L at "STP"STP, then can establish the following relationships:

color(white)(------)color(orange)[("22.4 L")/("1 mole") or ("1 mole")/("22.4 L")22.4 L1 moleor1 mole22.4 L

Knowing that, we can solve for the volume occupied by the helium gas,

(0.35 cancel"mole")/(1) * ("22.4 L")/(1 cancel"mole") = color(blue)"7.84 L"

as color(blue)"7.84 L"

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The answer makes sense because if "1 mole" occupies "22.4 L", then "0.35 moles" (roughly a third of the moles) will occupy a third of "22.4 L" ("if we round down 22.4 L to 21 L")

color(white)(--------)21/3 ~~"7 L"