How many moles of aluminum are present in 856g of aluminum sample?

Answer 1

Moles = Mass/ Relative Molecular Mass

Aluminum forms Al2 compounds, so the relative molecular mass is 2 * 13 = 26.

856/26 = 32.9 (3sf)

Answer 2

To determine the number of moles of aluminum present in 856g, you need to divide the mass by the molar mass of aluminum. The molar mass of aluminum is approximately 26.98 g/mol. So, 856g ÷ 26.98 g/mol ≈ 31.7 moles of aluminum are present in 856g.