Question

(a) What scientific principle or law is used in the process of balancing chemical equations? (b) In balancing equations, why should you not change subscripts in chemical formulas? (c) How would one write out liquid water, water vapor, aqueous sodium chloride, and solid sodium chloride in chemical equations?

Short answer

(a) The scientific principle or law used in balancing chemical equations is the Law of Conservation of Mass, which ensures the total mass of reactants equals the total mass of products. (b) We should not change subscripts in chemical formulas while balancing equations because they represent the molecular structure and composition of a substance. Changing subscripts would create a different chemical compound, disregarding the Law of Definite Proportions. (c) The correct notation for different states of matter in chemical equations are: Liquid Water - H₂O(l), Water Vapor - H₂O(g), Aqueous Sodium Chloride - NaCl(aq), and Solid Sodium Chloride - NaCl(s).

Step-by-step solution

(a) Scientific principle or law in balancing chemical equations

The scientific principle or law used in balancing chemical equations is the Law of Conservation of Mass. This law states that mass cannot be created or destroyed in any chemical reaction, so the total mass of the reactants must equal the total mass of the products. This means that the number of atoms of each element must be equal on both sides of the equation.

(b) Reason for not changing subscripts in chemical formulas

We should not change subscripts in chemical formulas while balancing equations because subscripts represent the actual molecular structure and composition of a substance. When we change the subscripts, we create a different chemical compound, altering the meaning of the equation and disregarding the Law of Definite Proportions. To balance an equation, we should instead adjust the coefficients (the numbers in front of the chemical formulas), which represent the number of molecules or moles of each substance involved in the reaction.

(c) Correct notation for different states of matter

To represent the different states of matter in chemical equations, you use the following notations: 1. Liquid Water: H₂O(l) Here, "l" stands for liquid, indicating that water is in its liquid state. 2. Water Vapor: H₂O(g) In this case, "g" denotes gas, which means that water is in its gaseous state as water vapor. 3. Aqueous Sodium Chloride: NaCl(aq) The notation "aq" signifies aqueous, which means that sodium chloride is dissolved in water, forming a solution. 4. Solid Sodium Chloride: NaCl(s) The letter "s" represents solid, indicating that sodium chloride is in its solid state.