# Which of the following statements is correct?

## (1) The mass of one mole of oxygen is 16.00 g. (2) One mole of an ideal gas occupies 22.4 L at NTP. (3) One mole of methane contains five atoms. (4) All of the above are incorrect.

Aug 20, 2017

(4) All of these are incorrect.

#### Explanation:

(1)

For ${\text{O}}_{2} , {M}_{\textrm{r}} = 32.00$.

∴ The mass of $\text{1 mol O"_2 = "32.00 g}$

Statement (1) is incorrect.

(2)

NTP is 1 atm and 20 °C.

The Ideal Gas Law is

$\textcolor{b l u e}{\overline{\underline{| \textcolor{w h i t e}{a a} p V = n R T \textcolor{w h i t e}{\frac{a}{a}} |}}} \text{ }$

V = (nRT)/p = (1 color(red)(cancel(color(black)("mol"))) × "0.082 06 L"·color(red)(cancel(color(black)("atm·K"^"-1""mol"^"-1"))) × 293.15 color(red)(cancel(color(black)("K"))))/(1 color(red)(cancel(color(black)("atm")))) = "24.06 L"

Statement (2) is incorrect.

(3)

1 ${\text{CH}}_{4}$ molecule contains 5 atoms.

${\text{1 mol CH}}_{4}$ contains ${\text{N}}_{\textrm{A}}$ molecules.

1 color(red)(cancel(color(black)("mol CH"_4 color(white)(l)"molecules"))) × (N_text(A) color(red)(cancel(color(black)(color(white)(l)"molecules CH"_4))))/(1 color(red)(cancel(color(black)("mol CH"_4 color(white)(l)"molecules")))) × "5 atoms"/(1 color(red)(cancel(color(black)("molecule CH"_4)))) = 5N_text(A) color(white)(l)"atoms"

Statement (3) is incorrect.

(4)

Statement (4) is correct because all the above are incorrect.