Arrange the following samples of oxygen gas ( $O_2$ ) in increasing order of the number of molecules present in them:

(I) $1.6 \text{ g}$ of $O_2$
(II) $22.4 \text{ L}$ of $O_2$ at STP
(III) $0.08 \text{ mol}$ of $O_2$
(IV) $32 \text{ u}$ of $O_2$

Question

Arrange the following samples of oxygen gas ( O_2 ) in increasing order of the number of molecules present in them: (I) 1.6 g of O_2 (II) 22.4 L of O_2 at STP (III) 0.08 mol of O_2 (IV) 32 u of O_2

Quantrex Academy · Accepted Answer

Correct answer: D. (IV) < (I) < (III) < (II)

Calculate the number of moles or molecules for each sample:

(I)

1.6 \text{ g}

of

O_2

: Moles

= \dfrac{1.6}{32} = 0.05 \text{ mol}

. Number of molecules

= 0.05 N_A

.

(II)

22.4 \text{ L}

of

O_2

at STP: Moles

= \dfrac{22.4}{22.4} = 1 \text{ mol}

. Number of molecules

= N_A

.

(III)

0.08 \text{ mol}

of

O_2

: Number of molecules

= 0.08 N_A

.

(IV)

32 \text{ u}

of

O_2

: Since the molecular mass of one

O_2

molecule is

32 \text{ u}

, this represents exactly

1

molecule.

Comparing the number of molecules:

1 < 0.05 N_A < 0.08 N_A < N_A

Thus, the increasing order is (IV) < (I) < (III) < (II).

Answer: (IV) < (I) < (III) < (II)

Arrange the following samples of oxygen gas ( O_2 ) in increasing...

Options

Correct answer

Step-by-step solution

More from Chapter