Answer:
0.776 ×10²³ atoms of oxygen
Step-by-step explanation:
Given data:
Mass of Al₂CO₃ = 10.0 g
Number of atoms of oxygen = ?
Solution:
Number of moles of Al₂CO₃:
Number of moles = mass/molar mass
Number of moles = 10.0 g/233.99 g/mol
Number of moles = 0.043 mol
1 mole of Al₂CO₃ contain 3 mole of oxygen.
0.043 ×3 mol = 0.129 mol
Number of atoms of oxygen:
1 mole contain 6.022×10²³ atoms
0.129 mol × 6.022×10²³ atoms / 1mol
0.776 ×10²³ atoms of oxygen