The density of aluminum is 2.7 g/cm3 and that of Al2O3 is about 4 g/cm3. Calculate the PB ratio for Aluminum. (Hint: The Pilling-Bedworth Ratio (PBR) gives the volume of oxide formed to the volume of metal atoms.) a) 1.28
b) 0.28
c) 0.75

1.28

Explanation:

Al = aluminium

Density of Al = 2.7g/cm³

Density of Al2O3 = 4g/cm³

Molecular weight of Aluminum = 27g/mol

Molecular weight of Al2O3= 101.96 g/mol

Pilling bedworth ratio = Rob

= M(Al2O3) * density of Al / n* molecular weight of Al * density of Al2O3

= 101.96g/mol x 2.7g/cm³/2x 27g/mol x 4g/cm³

= 275.292/216

= 1.28

From the calculation above 1.38nis the PB ratio for aluminum

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.