Answer: -
Magnesium reacts very slowly to form magnesium hydroxide and hydrogen gas. The balanced chemical equation for the reaction is
Mg + 2H₂O → Mg(OH)₂ + H₂
Explanation: -
Chemical symbol of magnesium = Mg
Chemical formula for magnesium hydroxide = Mg(OH)₂
Chemical formula for hydrogen gas = H₂
The other reactant with Mg must be water H₂O.
Thus the balanced chemical equation for the reaction is
Mg + 2H₂O → Mg(OH)₂ + H₂
Excess reactant : Na
NaCl produced : = 16.497 g
<h3>Further explanation</h3>
Given
Reaction(balanced)
2Na + Cl₂⇒ 2NaCl
20 g Na
10 g Cl₂
Required
Excess reactant
NaCl produced
Solution
mol Na(Ar = 23 g/mol) :
= 20 : 23 = 0.87
mol Cl₂(MW=71 g/mol):
= 10 : 71 g/mol = 0.141
mol : coefficient :
Na = 0.87 : 2 = 0.435
Cl₂ = 0.141 : 1 = 0.141
Limiting reactant : Cl₂(smaller ratio)
Excess reactant : Na
Mol NaCl based on mol Cl₂, so mol NaCl :
= 2/1 x mol Cl₂
= 2/1 x 0.141
= 0.282
Mass NaCl :
= 0.282 x 58.5 g/mol
= 16.497 g
