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Explain the roles of subscripts and coefficients in chemical equations. Balance a chemical equation when given the unbalanced equation. Explain the role of the Law of Conservation of Mass in a chemical reaction.
7 paź 2021 · Coefficients: Coefficients are numbers written in front of a chemical formula. They indicate the stoichiometry of the reactants and products, so you can see at a glance the mole ratio between them in a balanced equation. For example, in the formula 4H 2 O 2, “4” is the coefficient. By convention, the number “1” is omitted.
Stoichiometric coefficients are the numbers before an atom, ion, or molecule in a chemical reaction. They are essential because they establish the mole ratios between the reactants and products. In the above example, the mole ratio between C 2 H 5 OH and CO 2 is 1:2, and that between C 2 H 5 OH and H 2 O is 1:3.
Explain the roles of subscripts and coefficients in chemical equations. Balance a chemical equation when given the unbalanced equation. Explain the role of the law of conservation of matter in a chemical reaction.
Chemical reactions are balanced by adding coefficients so that the number of atoms of each element is the same on both sides. Stoichiometry describes the relationship between the amounts of reactants and products in a reaction.
For example, water (H 2 O) and hydrogen peroxide (H 2 O 2) are chemically distinct substances. H 2 O 2 decomposes to H 2 O and O 2 gas when it comes in contact with the metal platinum, whereas no such reaction occurs between water and platinum. Left: Example of changing coefficients or subscripts. Right: Platinum dissolving in hydrogen peroxide.
For a chemistry example, consider the reaction between one methane molecule (CH 4) and two diatomic oxygen molecules (O 2) to produce one carbon dioxide molecule (CO 2) and two water molecules (H 2 O). The chemical equation representing this process is provided in the upper half of the image below.
