The balanced equation for the reaction is as follows
2Al + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂
stoichiometry of Al to H₂SO₄ is 2:3
number of Al moles reacted - 15.0 mol
if 2 mol of Al react with 3 mol of H₂SO₄
then 15.0 mol of Al reacts with - 3/2 x 15.0 mol = 22.5 mol
22.5 mol of H₂SO₄ is required
If the element has a charge of +2 it has lost two electrons giving it an overall positive charge making it a cation. In order to find the number of electrons, take the elements atomic number and subtract two since it lost two electrons
Answer:
half-life = 3.8 days
total time of decay = 15.2 days
initial amount = 100. g
number of half-lives past: 15.2/3.8 = 4 half-lives
4 half-lives = 1/16 remains
100. g x 1/16 = 6.25 g
