For the chemical reaction: ALOH3 (s)
= Al2O3 (s)
+ H20 (l)
Calculate the mass of water formed when 100 g of Al(OH)3 is heated. (AI = 27: 0 - 16; H = 1)

35.1 g

Explanation:

Given data:

Mass of Al(OH)₃ = 100 g

Mass of water formed = ?

Solution:

Chemical equation:

2Al(OH)₃      →        Al₂O₃ + 3H₂O

Number of moles of Al(OH)₃:

Number of moles = mass/molar mass

Number of moles = 100 g/ 78 g/mol

Number of moles = 1.3 mol

now we will compare the moles of Al(OH)₃ with water.

                          Al(OH)₃         :          H₂O

                             2                :            3

                             1.3              :           3/2×1.3 = 1.95

Mass of water produced:

Mass = number of moles ×molar mass

Mass = 1.95 mol × 18 g/mol

Mass = 35.1 g