Question

Calculate the number of atoms in 44.8 litres of SO₂ at STP

Answer 1

Answer : The correct answer is 36.132 * 10²³ number of atoms in SO₂

Following steps can be used to convert 44.8 L to number of atoms .

Step 1 : Conversion of 44.8 L of SO₂ to mole.

STP is Standard Temperature and pressure condition where 1 mole of gas occupies 22.4 L of volume . Hence , volume can be converted to mole using formula :

$Mole = \frac{given volume }{ 22.4 L } * 1 mol$

Plugging value in above formula :

$Mole = \frac{44.8 L}{22.4 L} * 1 mol$

Mole = 2 mol of SO₂

Step 2: Conversion of mole of SO₂ to number of molecules .

1 mole of gas contains 6.022 * 10²³ number of molecules . Hence , mole can be converted to number of molecules by formula :

$Mole = \frac{number of atoms}{6.022 * 10^2^3 } * 1 mol$

Plugging values in above formula :

$2 mol = \frac{number of atom }{6.022 * 10^2^3} * 1 mol$

Multiplying both side by $\frac{6.022 * 10^2^3}{1 mol}$

$2 mol * \frac{6.022 * 10^2^3}{1 mol} = \frac{number of atm}{6.022 *10^2^3} * 1 mol * \frac{6.022 * 10^2^3}{1 mol}$

Number of molecules : 12.044 * 10²³ of SO₂

Since in one molecule of SO₂ , there are three atoms , 1 S atom and 2 O atoms , so number of atoms = 3 * 12.044 *10²³ = 36.132 * 10²³