Final answer:
a. multiplying the second equation by 2.
To balance the equation for the reaction between sodium and chlorine gas to form sodium chloride, a coefficient of 2 is used in front of NaCl, resulting in the balanced chemical equation: 2 Na + Cl2 → 2 NaCl.
Step-by-step explanation:
The student is asking about the process of balancing chemical equations, specifically the reaction between sodium (Na) and chlorine gas (Cl2) to form sodium chloride (NaCl).
Balancing chemical equations ensures that equal numbers of atoms for each element involved in the reaction are represented on the reactant and product sides, according to the Law of Conservation of Mass.
The initial equation, Na (s) + Cl2 (g) → NaCl (s), is not balanced because it does not have equal numbers of each type of atom on both sides of the equation.
To balance the equation, you need to ensure that there are equal numbers of sodium and chlorine atoms on both the reactant and product sides.
You can achieve this by placing a coefficient of 2 in front of NaCl to account for the two chlorine atoms in Cl2, resulting in the equation 2 Na (s) + Cl2 (g) → 2 NaCl (s).
This represents a balanced chemical equation with two sodium and two chlorines on both sides.
For some more complex redox reactions occurring in aqueous solutions, balancing may require the half-reaction method, but for this simple combination reaction, multiplying by simple integers is sufficient to achieve balance.