Q: What does the term ‘compound nomenclature’ refer to in chemistry? A: Compound nomenclature refers to the system of naming chemical compounds. It’s a systematic approach that helps to identify a compound from its name and vice versa.
- Q: What are the rules for naming ionic compounds? A: For ionic compounds, the name of the metal ion (cation) comes first, followed by the name of the nonmetal ion (anion). For example, NaCl is named Sodium Chloride. For transition metals that can have different charges, a roman numeral is used to denote the charge, such as Iron (III) Chloride for FeCl3.
- Q: What is a molecular compound? A: A molecular compound is a chemical compound whose simplest units are molecules. They usually consist of nonmetals. For example, water (H2O) is a molecular compound.
- Q: How are molecular compounds named? A: Molecular compounds are named using a prefix system. The first element is named with its elemental name, and the second element is named with its root plus the suffix -ide. Prefixes such as di-, tri-, tetra-, etc. are used to denote the number of atoms. For example, P2O5 is named Diphosphorus pentoxide.
- Q: What is a chemical reaction equation? A: A chemical reaction equation is a representation of a chemical reaction. The reactants (starting materials) are written on the left, and the products (ending materials) are written on the right. An arrow pointing from the reactants to the products shows the direction of the reaction.
- Q: What does a balanced chemical equation indicate? A: A balanced chemical equation indicates that the law of conservation of mass is being obeyed. In other words, the number of atoms of each element is the same on both the reactant and product sides of the equation.
- Q: What is a coefficient in a chemical equation? A: A coefficient in a chemical equation is a number placed in front of a chemical symbol or formula. It indicates the number of units (atoms, molecules, or ions) of that substance involved in the reaction.
- Q: What is the principle of charge balance in ionic compounds? A: The principle of charge balance states that the total positive charge must equal the total negative charge in an ionic compound. This is why the charges of ions are taken into account when naming these compounds.
- Q: How is water, a molecular compound, named and why? A: Water is named using its common name, not using the systematic naming convention. According to the systematic naming convention, it would be named Dihydrogen Monoxide, but the common name “water” is universally accepted.
- Q: How are acids named? A: The names of acids depend on whether the anion contains oxygen. If the anion does not contain oxygen, the acid is named with the prefix “hydro-” and the suffix “-ic.” If the anion contains oxygen, the suffix “-ic” or “-ous” is used depending on the type of oxyanion. For example, HCl is hydrochloric acid, while H2SO4 is sulfuric acid.
- Q: What are polyatomic ions? A: Polyatomic ions are ions that are composed of two or more atoms covalently bonded or of a metal complex acting as a single unit with a net charge.
- Q: How are polyatomic ions named? A: Polyatomic ions are named based on their composition. For example, the ion SO4^2- is named sulfate, and NO3^- is nitrate. There are also rules for ions with different numbers of oxygens.
- Q: What is a subscript in a chemical formula? A: A subscript in a chemical formula indicates the number of atoms of the element that it follows. For example, in H2O, the subscript 2 after the H indicates there are two hydrogen atoms.
- Q: How are hydrates named? A: Hydrates are named by the compound’s name followed by a prefix denoting the number of water molecules per formula unit. For example, CuSO4·5H2O is Copper (II) sulfate pentahydrate.
- Q: What is a precipitation reaction? A: A precipitation reaction is a type of chemical reaction in which two soluble salts in aqueous solution combine to form an insoluble salt, or precipitate.
- Q: What is a reaction stoichiometry? A: Reaction stoichiometry refers to the numerical relationships between reactants and products in a balanced chemical reaction. It is used to determine the amount of products that will be formed or the amount of reactants needed for the reaction.
- Q: What are organic compounds? A: Organic compounds are generally any chemical compounds that contain carbon-hydrogen bonds. They are often associated with living organisms.
- Q: How are alkanes named? A: Alkanes are named according to the number of carbon atoms in their chain. The names use a prefix to indicate the number of carbons and the suffix “-ane.” For example, methane (CH4), ethane (C2H6), and propane (C3H8).
- Q: What is the role of a catalyst in a chemical reaction? A: A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy, but it is not consumed in the reaction. It can appear in the reaction equation but is usually written above or below the arrow.
Q: What is a reversible reaction? A: A reversible reaction is a chemical reaction where the reactants form products, which react together to give the reactants back. A double arrow (⇌) is used to indicate this process.
