Question

find the total no of atom present 448ml of so3 gas . if volume measured at stp​

Answer 1

Given :

• Volume of SO₃ at STP = 448 ml

To find :

Number of atoms of SO₃ present

Solution :

At STP

• Temperature = 0° C = 273 K
• Pressure = 1 atm

Therefore , R = 0.082 L atm K⁻¹ mol⁻¹

Now , volume is given in ml, so we will change it into L

V = 448 ml = 448/1000 L

V = 0.448 L

Using ideal gas equation, PV = nRT we will find number of mole of gas present

$\sf \implies \: 1 \: atm \: \times \: 448 \: ml \: = \: n \times (0.082 \: {L } \: atm \: {K}^{ - 1} {mol}^{ - 1} ) \times 273K$

$\sf \implies \:n \: = \: \dfrac{1 \: atm \: \times \: 0.448 \:L \: }{(0.082 \: {L } \: atm \: {K}^{ - 1} {mol}^{ - 1} ) \times 273K}$

$\sf \implies \:n \: = \: \dfrac{ \: 0.448 \: \: }{(0.082 \: \: \: {mol}^{ - 1} ) \times 273}$

$\sf \implies \:n \: = 0.02mol$

Number of mole of SO₃ present = 0.02 mol

_______________________________________________

Now we will find number of atoms by using Formula given below

Number of atoms = Number of mole × Avogadro's Number × atomicity

• Atomicity of SO₃ = Number of atom of S in SO₃ + Number of atoms of O in SO₃

➝ Atomicity of SO₃ = 1 + 3

➝ Atomicity of SO₃ = 4

Therefore

Number of atoms of SO₃ = 0.02 × 6.02 × 10²³ × 4

➝ Number of atoms of SO₃ = 0.4816 × 10²³

➝ Number of atoms of SO₃ = 4.816 × 10²² atoms

_______________________________________________

ANSWER : 4.816 × 10²² atoms