Question

Total number of moles of oxygen atoms in $3$ litres $O_3\left(g\right)$ at ${27}^{\circ }$C and 8.21 atm are

• A. 3
• B. 1
• C. 2
• D. none of these

Answer 1

The correct option is A 3

Molar gas volume at STP = 22.4 litres

We need to convert this volume to the volume the gas would occupy at STP

p1 = 8.21 atm p2 = 1 atm

v1 = 3 litres v2 = ?

t1 = 27 + 273 = 300 k t2 = 273K

p1v1/t1 = p2v2/t2

(8.21x3)/300 = (1xv2)/273

From which

v2 = 22.4133 litres

Number of moles of O3 = 22.4133/22.4 = 1 mole

Each O3 molecule has 3 atoms of O

Number of moles of oxygen atoms = 3 x 1 = 3