What volume is occupied by a 64*g64g mass of oxygen gas confined in a piston under conditions of "STP"STP?

4 Answers
Oct 28, 2017

Approx. 44*L44L..........

Explanation:

The molar volume of "STP"STP is usually quoted at 22.4*L*mol^-122.4Lmol1 (these definitions vary according to the syllabus you follow....

For the molar quantity of this mass of dioxygen gas we have....

(64.0*g)/(32.0*g*mol^-1)=2*mol64.0g32.0gmol1=2mol....

And so to find the volume occupied by the molar quantity, we take the product....

"Moles"xx"molar mass"Moles×molar mass == 2*molxx22.4*L*mol^-1=??*L2mol×22.4Lmol1=??L

Note that you must simply know that ALL elemental gases SAVE the NOBLE GASES, are bimolecular, i.e. dinitrogen, dioxygen, difluorine, dichlorine....

Oct 28, 2017

Use the molar volume ((22.4 "L")/("mol"22.4Lmol). This value can only be used at "STP"STP conditions (0^@" C" " or " 273 " K", and 1 " atm")(0 C or 273 K,and1 atm).

Explanation:

We can use dimensional analysis to convert from:

color(red)("g") " O"_2 -> color(red)(" moles ") "of" " O"_2 -> color(red)("L ")"of" " O"_2 " at STP"g O2 moles of O2L of O2 at STP

First, let's calculate the molar mass of "O"_2O2 using the Periodic Table:

"O"_2 = 2(16.00) = 32.00 "g"/"mol"O2=2(16.00)=32.00gmol

Now, we are ready to begin:

64.0" g" " O"_2 ((1" mol" " O"_2)/(32.00" g" " O"_2))((22.4" L")/(1" mol")) = 44.80 " L O"_264.0 g O2(1 mol O232.00 g O2)(22.4 L1 mol)=44.80 L O2

Your final answer is therefore 44.8 " L O"_(2("g"))44.8 L O2(g) with significant figures and proper units.

I hope that helps!

Oct 28, 2017

45 dm^345dm3 rounded.

Explanation:

Molar mass of O_2O2 molecule is 31.9

Number of moles = mass in grams/ molar mass.

64.0/31.9= 2.0164.031.9=2.01 moles.

1 mole of of O_2O2 at S.T.P = 22.4 dm^322.4dm3

So:

2.01 xx22.4= 45.024 dm^32.01×22.4=45.024dm3

Oct 28, 2017

48 dm^3dm3 OR 44.8 dm^3dm3

Explanation:

At GCSE level, I was taught that one mole of gas occupies a volume of 24 dm^3dm3 (or 24 litres). However when I searched online and learned that the accurate volume 1 mole of gas occupies is 22.4 dm^3dm3 (or 24 litres).

I will show you the calculation for both.

First we need to calculate how many moles of O_2O2 are in 64.0g using the equation: (mass)/(mr)massmr=moles

mass=64.0g
Mr( O_2O2)= 16*2162=32

moles= 64.0/32=264.032=2

If 1 mole of O_2O2 = 24dm^324dm3
2 moles of O_2O2 = 48dm^348dm3

If 1 mole of O_2O2 = 22.4dm^322.4dm3
2 moles of O_2O2 = 44.8dm^344.8dm3