Question

how many number of molecules in 36.8g C₂H₅OH?

Answer 1

Given:-

→ Mass of C₂H₅OH = 36.8g

To find:-

→ Number of molecules in 36.8g

of C₂H₅OH

Solution:-

• Atomic mass of Carbon (C) = 12u

• Atomic mass of Hydrogen (H) = 1u

• Atomic mass of Oxygen (O) = 16u

Molecular mass of C2H5OH :-

= 12×2+5×1+16+1

= 24+5+17

= 46u

∵ Molecular mass of C₂H₅OH is 46u

∴ Molar mass of C₂H₅OH is 46g.

Number of moles in 36.8g of C₂H₅OH :-

= Given mass/Molar mass

= 36.8/46

= 0.8 mole

• Avogadro Number = 6.022×10²³

Number of molecules:-

= No of moles × Avogadro number

= 0.8×6.022×10²³

= 4.8176×10²³ molecules

Thus, 4.8176×10²³ molecules are there in 36.8 g of C₂H₅OH.