What is the number of moles in 526 l o2 at stp?

The correct answer is : 23.5 mol of O2 .

At STP ( Standard Temperature and potential ) 1 mole of gas has 22.4 L of volume .The follow can be expressed as :

Given volume of O2 gas = 526 L

Plugging value in the formula :

Mole of O2 gas at STP = 23.5 mol

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation: