Question

One mole of oxygen gas at STP is equal to ___.

• A. $6.022\times {10}^{23}$ molecules of oxygen
• B. 32 g of oxygen
• C. $6.022\times {10}^{23}$ atoms of oxygen
• D. 16 g of oxygen

Answer 1

Answer: (A), (B)

32 g of oxygen

Analysing one mole of oxygen at STP

1 mole = $6.022\times {10}^{23}$ molecules of oxygen

Molecular weight of $O_2$ = 32g

So, 1 mole of $O_2$ gas at STP = $6.022\times {10}^{23}$ molecules of $O_2$ (Avogadro number) = 32 g of $O_2$.

Calculating the unknown

No. of molecules in 1 mole of $O_2=6.022\times {10}^{23}$

No. of atoms in 1 mole of $O_2=2\times 6.022\times {10}^{23}$
$=12.044\times {10}^{23}$

Similarly, weight of 1 mol of $O_2=(16\times 2)g=32gofoxygen$

Hence, from above data it is concluded that option A and D are the correct one