Answer:
1.12 moles of MgCl₂
Explanation:
Given parameters:
Mass of Mg(OH)₂ = 65g
Unknown:
Number of moles of MgCl₂ = ?
Solution:
To solve this problem, obtain a balanced reaction equation first;
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
From the reaction above, this is a typical neutralization process in which an acid reacts with a base to produce salt and water only.
Let's proceed; the reactant in excess is the HCl, acid. The other reactant is the Mg(OH)₂ and it must be the limiting reactant. A limiting reactant is one that is given in short supply and determines the extent of the reaction.
Find the number of moles of Mg(OH)₂;
Number of moles = [tex]\frac{mass}{molar mass} \\[/tex]
Molar mass of Mg(OH)₂ = 24 + 2(16 + 1) = 58g/mol
Number of moles = [tex]\frac{65}{58}[/tex] = 1.12moles
The balanced reaction equation shows that;
1 mole of Mg(OH)₂ gives 1 mole of MgCl₂
1.12 mole of Mg(OH)₂ will produce 1.12 moles of MgCl₂
