Chemical equations a and c are not balanced due to the unequal number of sodium and potassium atoms, respectively, on both sides. Equation b is balanced with equal numbers of carbon, hydrogen, and oxygen atoms. Adjusting coefficients can balance equations a and c.
Step-by-step explanation:
To determine if a chemical equation is balanced, one must ensure that the number of atoms of each element is the same on both the reactant and product sides of the equation. Now let's analyze the given equations.
Equation a. 2Na(s) + O₂(g) → 2Na₂O(s) is not balanced because there are 2 sodium atoms on the reactant side and 4 sodium atoms on the product side.
Equation b. CH4(g) + 2O2(g) → CO₂(g) + 2H₂O(l) is balanced as there are equal numbers of each atom on both sides of the equation.
Equation c. AgNO3(aq) + 2KCl(aq) → AgCl(s) + KNO3(aq) is not balanced because there are 2 potassium atoms on the reactant side and only 1 on the product side.
To balance the unbalanced equations, coefficients must be adjusted. For example, equation a will be balanced by changing the coefficient of the product Na₂O to 2, resulting in 4Na + O₂ → 2Na₂O. In equation c, to balance potassium and chlorine atoms, the correct equation should be AgNO3(aq) + KCl(aq) → AgCl(s) + KNO3(aq).