Final answer:
The questions involve balancing chemical equations for reactions involving sodium and water, magnesium and hydrochloric acid, and potassium bromide and chlorine gas.
Step-by-step explanation:
The student is asking about completing and balancing chemical equations, which are fundamental concepts in Chemistry. For a reaction between solid sodium and water, the balanced equation is:
2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g)
This equation represents the reaction of sodium metal with water producing sodium hydroxide and hydrogen gas.
Magnesium reacting with hydrochloric acid would be balanced as:
Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)
This equation demonstrates the reaction between magnesium and hydrochloric acid to produce magnesium chloride and hydrogen gas.
Finally, the reaction between potassium bromide and chlorine gas is:
2KBr(aq) + Cl₂(g) → 2KCl(aq) + Br₂(l)
This equation shows how potassium bromide and chlorine react to yield potassium chloride and bromine liquid.