Question

What is the number of atoms in 50g of copper (Cu) (Atomic number of Cu=63.5u)

Answer 1

QUESTION : What is the number of atoms in 50g of copper (Cu) (Atomic mass of Cu=63.5u)

Given :

• Weight of Copper = 50g
• Average atomic mass of Cu = 63.5u

Formula used :

• Number of mole = weight ÷ molar mass
• Number of atoms = number of mole × avogadro's number

Solution :

Molar mass of Cu = 63.5g g/mol

=> Number of mole of Cu = weight of Cu ÷ molar mass of Cu

=> Number of mole of Cu = 50 ÷ 63.5

=> Number of mole of Cu = 0.787 mol

Number of atoms of Cu = Number of mole × avogadro's number

=> Number of atoms of Cu = (0.787) × (6.02×10²³)

=> Number of atoms of Cu = 4.74 × 10²³ atoms

ANSWER :

Number of atoms of Cu = 4.74 × 10²³ atoms