How many grams of aluminum sulfate form when 3.90 grams of aluminum is placed in 13.65 grams of sulfuric acid?

Respuesta :

Neetoo

Answer:

Mass = 17.12 g

Explanation:

Given data:

Mass of Al = 3.90 g

Mass of H₂SO₄ = 13.65

Mass of aluminium sulfate = ?

Solution:

Chemical equation:

3H₂SO₄ + 2Al   →  Al₂(SO₄)₃ + 3H₂

Now we will calculate the number of moles of each reactant.

Moles of H₂SO₄:

Number of moles = mass/ molar mass

Number of moles = 13.65 g/ 98.079 g/mol

Number of moles = 0.14 mol

Moles of Al:

Number of moles = mass/ molar mass

Number of moles = 3.90 g/ 27 g/mol

Number of moles = 0.14 mol

Now we will compare the moles of aluminium sulfate with sulfuric acid and aluminium.

                           H₂SO₄       :         Al₂(SO₄)₃

                               3            :              1

                           0.14            :          1/3×0.14 = 0.05

                              Al            :           Al₂(SO₄)₃

                               2            :             1

                            0.14           :        1/2×0.14 = 0.07

The number of moles of aluminium sulfate produced by sulfuric acid are less so it will limiting reactant and limit the amount of aluminium sulfate.

Mass of aluminium sulfate:

Mass = number of moles × molar mass

Mass = 0.05 mol × 342.15 g/mol

Mass = 17.12 g