<span>The correct answer is option 4. It is the hydroxide ions that is produced by an Arrhenius base in water. According to Arrhenius, acid-base reactions are characterized by acids which forms hydronium ions in water and bases which dissociates in aqueous solution to form hydroxide ions. </span>
The formula for specific gravity is:

where
is the density of the substance and
is the density of water.
The density of water,
= 
Substituting the values in above formula we get,


The formula of density is:

The density of mercury is 
The mass of mercury is 
Substituting the values in density formula:


Answer:
Mg(s) + Sn²⁺(aq) ⇄ Mg²⁺(aq) + Sn(s)
Explanation:
Let's consider the following molecular equation.
Mg(s) + SnSO₄(aq) ⇄ MgSO₄(aq) + Sn(s)
The full ionic equation includes al the ions and the species that do not dissociate in water.
Mg(s) + Sn²⁺(aq) + SO₄²⁻(aq) ⇄ Mg²⁺(aq) + SO₄²⁻(aq) + Sn(s)
The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the species that do not dissociate in water.
Mg(s) + Sn²⁺(aq) ⇄ Mg²⁺(aq) + Sn(s)