Question

How many moles of a gas occupy 4.167 L at 79.97 kPa at 30.0°C.

Answer 1

please refer to the attachment file given mate.

hope this answer will be helpful to you dear.

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please mark me as a brainliest........xD

Answer 2

Explanation:

1) Solve for the moles using PV = nRT:

n = PV / RT

n = [(79.97 kPa / 101.325 kPa atm¯1) (4.167 L)] / [(0.08206 L atm mol¯1 K¯1) (303.0 K)]

n = 0.13227 mol

2) Divide the grams given (20.83) by the moles just calculated above:

20.83 g / 0.13227 mol = 157.5 g/mol

Notice that, in the two problems just above, the I converted the pressure unit given in the problem to atmospheres. I did this to use the value for R that I have memorized. There are many different ways to express R, it's just that L-atm/mol-K is the unit I prefer to use, whenever possible.

Also, you cannot use molar volume since the two problems just above are not at STP.