Calculate the number of moles and molecules of acetic acid present in

1.	Calculate the number of moles and molecules of acetic acid present in 22 g of it.
Answer» Given : Mass of acetic acid = 22 g To find : The number of moles and molecules of acetic acid Formulae : Number of moles = \(\frac{Mass\,of\,a\,substance}{Molar\,mass\,of\,a\,substance}\) Number of molecules = Number of moles × Avogadro’s constant Calculator : Mass of acetic acid = 22 g Molecular mass of acetic acid, CH₃COOH = (2 × Average atomic mass of C) + (4 × Average atomic mass of H) + (2 × Average atomic mass of O) = (2 × 12 u) + (4 × 1 u) + (2 × 16 u) = 60 u ∴ Molar mass of acetic acid = 60 g mol^-1 Number of moles = \(\frac{Mass\,of\,a\,substance}{Molar\,mass\,of\,a\,substance}\) = \(\frac{22\,g}{60\,g\,mol^{-1}}\) = 0.367 mol Now, Number of molecules of acetic acid = Number of moles × Avogadro’s constant = 0.367 mol × 6.022 × 10²³molecules/mol = 2.210 × 10²³molecules ∴ Number of moles = 0.367 mol Number of molecules of acetic acid = 2.210 × 10²³ molecules.

Calculate the number of moles and molecules of acetic acid present in 22 g of it.

Answer»

Given :

Mass of acetic acid = 22 g

To find :

The number of moles and molecules of acetic acid

Formulae :

Number of moles = \(\frac{Mass\,of\,a\,substance}{Molar\,mass\,of\,a\,substance}\)

Number of molecules = Number of moles × Avogadro’s constant

Calculator :

Mass of acetic acid = 22 g

Molecular mass of acetic acid,

CH₃COOH

= (2 × Average atomic mass of C) + (4 × Average atomic mass of H) + (2 × Average atomic mass of O)

= (2 × 12 u) + (4 × 1 u) + (2 × 16 u)

= 60 u

∴ Molar mass of acetic acid = 60 g mol^-1

Number of moles = \(\frac{Mass\,of\,a\,substance}{Molar\,mass\,of\,a\,substance}\)

= \(\frac{22\,g}{60\,g\,mol^{-1}}\)

= 0.367 mol

Now,

Number of molecules of acetic acid = Number of moles × Avogadro’s constant

= 0.367 mol × 6.022 × 10²³molecules/mol

= 2.210 × 10²³molecules

∴ Number of moles = 0.367 mol

Number of molecules of acetic acid = 2.210 × 10²³ molecules.