Answer:
1.765 dm³
Step-by-step explanation:
Data Given:
Number of atoms of Ar = 4.91×10²² atoms
Volume of gas at STP = ?
Solution:
First we have to find number of moles of Argon
The formula used for this purpose
No. of moles = no. of atoms / Avogadro's number
where as
Avogadro's number = 6.23 x 10²³
Put values in the equation
No. of moles = 4.91×10²² atoms / 6.23 x 10²³
No. of moles = 0.0788
So,
Number of moles of Ar is 0.0788
Now
we have to find volume of argon gas
Formula used for this purpos
No. of moles = Volume / molar volume
modified form of the above equation at STP for Argon
No. of moles Ar = Volume of Ar / 22.4 dm³/ mol . . . . . .(1)
Put values in equation 1
0.0788 = Volume of Ar / 22.4 dm³/ mol
rearrange above equation
Volume of Ar = 0.0788 x 22.4 dm³/ mol
Volume of Ar = 1.765 dm³
So,
the volume of 4.91×10²²atoms of Ar at STP is 1.765 dm³