Balanced Chemical Equations
A balanced chemical equation represents a chemical reaction using the formula of the reactants and products. It shows the number of units of each substance involved.
Including State Symbols
Sometimes, balanced chemical equations include state symbols in brackets after each formula. These symbols indicate the physical state of the substance. For example, (S) represents solid, (L) represents liquid, (G) represents gas, and (aq) represents an aqueous solution. An aqueous solution forms when a substance dissolves in water. It's important to note that H₂O (L) is liquid, H₂0 (G) is steam, and H₂O (S) is ice. Additionally, HCI (G) represents hydrogen chloride gas, while HCl (aq) represents hydrochloric acid.
Balancing an Equation
The law of conservation of mass states that no atoms are lost or made during a chemical reaction. Therefore, the mass of the products is equal to the total mass of the reactants. Chemical reactions can be represented by symbol equations, and a balanced symbol equation has the same number of atoms of each element on both sides of the arrow. To balance an equation, numbers can be added to the left of one or more formulas.
Example of Balancing an Equation: Reaction Between Nitrogen and Hydrogen
Step 1: Check to see if there are an equal number of atoms of each element on both sides. In this example, N₂ + H₂ → NH₃, there aren't.
Step 2: There are two nitrogen atoms on the left, but only one on the right, so put a coefficient of 2 on the left of NH₃. The equation becomes N₂ + H₂ → 2NH₃.
Step 3: Check again. There are two hydrogen atoms on the left, but (2 x 3) = 6 on the right, so put a coefficient of 3 in front of the H₂. The equation becomes N₂ + 3H₂ → 2NH₃.
Step 4: Check again to see if there are equal numbers of each element on both sides. In this case, there are – two nitrogen atoms and six hydrogen atoms.
Step 5: Add the state symbols if asked. The resulting balanced chemical equation is N₂ (g) + 3H₂ (g) → 2NH₃ (g).
Balanced Chemical Equations Representation
Balanced chemical equations only show formulae, not names. A balancing number, written in normal script, multiplies all the atoms in the substance next to it. It is important to include state symbols if necessary.
By understanding the process of balancing chemical equations and the law of conservation of mass, one can accurately represent chemical reactions and their products. This knowledge is essential in chemical calculations and understanding the fundamental principles of chemistry.
