In the reaction of aluminum with sulfuric acid, 75.5 g of aluminum sulfate was formed.

In the reaction of aluminum with sulfuric acid, 75.5 g of aluminum sulfate was formed. Calculate the mass and amount of the aluminum substance that has reacted.

Aluminum with concentrated and dilute sulfuric acid reacts differently, but the coefficients before aluminum and aluminum sulfate in both reactions are the same, so for simplicity we will use dilute acid:
2Al + 3H2SO4 = Al2 (SO4) 3 + 3H2.
It is known that from 2 * 27 g of aluminum 342 g of sulfate (based on molar masses) are formed. Then:
2 * 27 g – 342 g
x g – 75.5 g.
x = 11.9 g is the desired mass of aluminum.
The amount of substance is calculated by the formula:
n = m / Mr = 11.9 / 27 = 0.4 mol.