Question

An aluminium sample has 54g. What is the mass of same no. Of Mg atoms

Answer 1

mole of Al=given weight of Al/molar weight of Al
=54/27=2mole

now,
mole of Mg=weight of Mg/molar weight of Mg
2=weight of Mg/24g

weight of Mg=48g

Answer 2

We know that:

Mole=given mass/molar mass

Then, moles of aluminum = 54/27 = 2.

A/c to question ,

For 2 moles of magnesium it's mass is 2×24=48g.

Hence, the required mass for same number of magnesium atoms is 48g.