Ionic Compounds and Lewis Diagrams

Ionic compounds are formed by the electrostatic attraction between positively charged ions (cations) and negatively charged ions (anions).

Ionic compounds are typically solids at room temperature due to the strong electrostatic forces holding the ions together. These forces require significant energy to overcome, leading to high melting and boiling points.

Ionic compounds are often soluble in water, which is a polar solvent. The polar water molecules can surround and separate the ions, breaking down the ionic lattice.

Ionic compounds are insulators in their solid state because the ions are fixed in a crystal lattice and cannot move freely to conduct electricity. However, when dissolved in water, the ions become mobile and can conduct electricity, making the solution a conductor.

A Lewis diagram shows the arrangement of valence electrons around an atom. For cations, show no electrons as electrons are lost. For anions, show original valence electrons with dots and gained electrons with 'x'. Enclose the symbol in square brackets with the charge outside.

Binary ionic compounds contain a metal with a single charge and a non-metal. These are named by combining the metal's name with the non-metal's name, ending in '-ide'.

Multivalent ionic compounds involve transitional metals that can form ions with different charges. The Roman numeral in the name indicates the charge of the metal ion.

The sum of the positive and negative charges in an ionic compound must always equal zero. This principle is used to determine the chemical formula of ionic compounds.

A compound formed when two nonmetals share electrons to create a stable molecule.

A group of atoms held together by covalent bonds, forming a single unit.

A chemical bond formed when two atoms share electrons.

An ion made up of two or more atoms that acts as a single unit with a specific charge.

A method of naming covalent compounds using Greek prefixes to indicate the number of atoms of each element.

Nitrogen Trihydride, NH3, is formed when nitrogen (N) and hydrogen (H) atoms share electrons. This sharing creates a covalent bond, as opposed to the transfer of electrons in ionic compounds.

Lewis diagrams illustrate how electrons are shared in covalent compounds, showing the arrangement and location of those electrons.

Simplified representations of covalent molecules, structural diagrams emphasize the shared electrons in the covalent bonds using lines, which represent two shared electrons.

Diatomic molecules are those that exist naturally as pairs of atoms covalently bonded together.

Covalent bonds form when two non-metal atoms mutually share electrons to achieve stability.

In a chemical reaction, the total mass of the substances involved remains constant, no matter how they are rearranged. This principle is called the law of conservation of mass.

Synthesis reactions happen when two or more substances (reactants) combine to form a single, more complex substance (product).

Decomposition reactions involve a single, complex substance breaking down into two or more simpler substances.

A chemical reaction where one element replaces another in a compound. The element that is more reactive will replace the less reactive element. For example, zinc reacting with copper (II) sulfate results in zinc sulfate and copper.

A chemical reaction where two ionic compounds exchange their ions. This occurs when the metal and nonmetal from one compound swap places with the metal and nonmetal from the other compound. For example, silver nitrate and sodium chloride react to form silver chloride and sodium nitrate.

A chemical reaction where a substance reacts with oxygen to produce energy, carbon dioxide and water (and possibly other products). For example, burning wood or propane in a barbecue grill.

A combustion reaction where there is enough oxygen present for all of the fuel to react completely. This results in the production of carbon dioxide and water. For example, burning a Bunsen burner with an open airhole.

A combustion reaction where there is limited oxygen available. This results in the production of carbon monoxide, carbon soot and water. For example, burning a candle with a limited oxygen supply.

A reaction involving the burning of hydrogen with oxygen to produce water and energy. This is a clean and efficient process. However, the production of hydrogen is expensive and requires energy.

A theory that defines acids as proton donors and bases as proton acceptors. It helps explain how acids and bases interact.

A substance that conducts electricity when dissolved in solution. Acids, bases, and salts are all electrolytes.

A substance that dissolves fully into ions in solution, completely dissociating and making a good conductor of electricity. Examples include strong acids like hydrochloric acid (HCl) and strong bases like sodium hydroxide (NaOH).

A substance that only partially dissolves into ions in solution, some molecules remain intact. Examples include weak acids like acetic acid (CH3COOH) and weak bases like ammonia (NH3).

A substance that contains an excess of hydroxide ions (OH-). They are often referred to as alkali. They typically have a slippery feel, bitter taste, and corrosive properties. For example, soap, ammonia, and oven cleaner.

A substance that contains an excess of hydrogen ions (H+). They typically have a sour taste, are corrosive, and can react with metals. Examples include vinegar (acetic acid), lemon juice (citric acid), and battery acid.

A reaction between an acid and a base that results in the formation of water and a salt. The reaction cancels out the acidity or basicity of the original solutions. For example, reacting hydrochloric acid (HCl) with sodium hydroxide (NaOH) produces water (H2O) and sodium chloride (NaCl).

A scale that measures the acidity or basicity of a solution. A pH of 7 is neutral, below 7 is acidic, and above 7 is basic. For example, pure water has a pH of 7, while lemon juice has a pH of 2.

A substance that changes color depending on the pH of a solution. This helps to indicate the acidity or basicity of a substance. Examples include litmus paper, phenolphthalein, and bromothymol blue.