basic chem chap 3 Compounds and Chemical Bonds

ionic compound

metal and nonmetal (or a polyatomic ion)

molecular compound

two or more nonmetals

acid

hydrogen and one or more nonmetals

Alkali metals and alkaline earth metals form only one type of ion so they DONT have roman numerals

ionic compounds

Does the cation (metal) form more than one type of ion?

H

When names end in acid, formulas start with

-ic acid

when naming oxyacids, if polyatomic ion name ends in –ate, then change ending to

–ous acid

If polyatomic ion name ends in –ite, then change ending to

binary acids

What do you call a compound made of H⁺ + nonmetal anion ?

Naming Rule:

• Start with “hydro–”

• Add the root of the nonmetal

• End with “-ic acid”

oxyacids

What do you call a compound made of H⁺ (cation) + polyatomic anion containing oxygen?

Naming Rules:

• If the polyatomic anion ends in “-ate” → “-ic acid”

• If the polyatomic anion ends in “-ite” → “-ous acid”

acids

What do you call molecular compounds that produce H⁺ ions when dissolved in water (aqueous)?

• They are covalently bonded molecules.

• In water, they ionize to release H⁺ (protons).

Acids are composed of H+ first (hydrogen cation) and one or more nonmetals

What are acids composed of?

oxyanions

• Most polyatomic ions are _, anions containing oxygen and another element

• Most of the time, an oxygen ion will have a 2– charge

• When a series of _ contains different numbers of oxygen atoms, they are named according to the number of oxygen atoms in the ion

covalent bonds

between two or more nonmetals

• When a nonmetal bonds with another nonmetal, they share some of their electrons to satisfy all octets

• They compose a molecule

Law of definite proportions

• Elements compose of a given compound always occur in fixed or definite proportions in all samples of the compound

• All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements

Ionic compound

• metal and one or more nonmetal together

• net charge of 0

cation

metal loses electron

anion

nonmetal gains electron

physical

ice melts

chemical

propane burns in air

physical

lead is a very dense metal

chemical

leaves turn color in the fall

physical

magnesium is very malleable

physical

Bromine is a dense dark-red, pungent smelling liquid

chemical

Sulfur burns with a dark blue flame

chemical changes

• Alters the composition of matter

  • Atoms rearrange, transforming the original substances into different substances

  • Decomposition of water, rusting of iron, burning of wood, acid corrosion of metals

• Involves composition change

  ◦ Particles are different before and

  after

physical change

• Alters the physical state and/or appearance, but not the composition

physical change

• The atoms or molecules that compose a substance do not change their identity during a physical change

physical change

• Boiling water, shredding paper, melting ice, painting car

physical change

• Temperature can alter physical properties

physical change

• Change caused by heating can be reversed by cooling

chemical properties

• Properties that a substance shows as

it interacts with, or transforms into,

other substances

• Flammability, corrosiveness

physical change

• Properties a substance shows by itself without interacting with another substance

  • Color, melting point, boiling point

  • Basically, it’s a description

• NO composition change

  ◦ Particles remain the same before

  and after

chromatography

a mixture in solution is passed through a medium in which the components move at different rates

distillation

a mixture is heated to boil off the more volatile liquid

filtration

a mixture of an insoluble solid and liquid is poured through some type of filter

decanting

• carefully pouring off a liquid into another container

  • Works with mixtures such as sand and water

  • Two immiscible (non-mixing) liquids

mixtures

• contain several substances with proportions that vary from

  one sample to another

  ◦ Variable compositions

compound

• A substance composed of two or more elements in fixed definite proportions

  • Sugar (fructose) is nothing but carbons, hydrogens, and oxygens

  • Table salt is composed of sodium and chlorine in crystals

pure substances

• are composed of only one type of atom or molecule

  • Helium and water are both pure substances

◦ Element : Helium = nothing but He atoms

◦ Compound : Water = a bunch of H2O molecules

molecular element

• A structure that consist of two or more atoms of the same element that are chemically bound together and behave as a single, independent unit

◦ H2, N2, S8, etc.

atomic element

• The simplest type of substance with unique physical and chemical properties

  • Consists of only one type of atom

  • Cannot be broken down into any simpler substances by physical or chemical means

element

• Pure substance made of only one type of atom.

• Not bonded with other elements.

• Example: O2 (oxygen gas) or Fe (iron metal).

bases

• Compounds that produce OH⁻ (hydroxide ions) in water.

• Usually contain a metal + OH.

• Example: NaOH (sodium hydroxide).

acids

• Compounds that produce H⁺ (protons) in water.

• Usually start with H in their formula.

• Example: HCl (aq) → hydrochloric acid.

• Two types:

  • Binary acids (H + single element, e.g., HBr).

  • Oxoacids (H + polyatomic ion with oxygen, e.g., H2SO4).

Binary acids

• (H + single element, e.g., HBr).

Oxoacids

•  (H + polyatomic ion with oxygen, e.g., H2SO4).

molecular/covalent compounds

• Formed between two or more nonmetals.

• Involves sharing of electrons between atoms.

• Often named using Greek prefixes (mono-, di-, tri-, etc.).

• Example: CO2 (carbon dioxide).

ionic compound

A bond formed by the transfer of electrons from a metal to a nonmetal; held together by electrostatic attraction (e.g., NaCl).

ionic bonds

• Transfer of electrons from a metal (forms a cation, +) to a nonmetal (forms an anion, –).

• Held together by: Electrostatic attraction between oppositely charged ions.

• Example: NaCl (sodium chloride).

covalent bonds

A bond formed by the sharing of electrons between two nonmetals.

• Nonpolar covalent = equal sharing (H2, CH4).

• Polar covalent = unequal sharing (H2O, HCl).

metallic bonds

A bond in metals where atoms share a "sea of delocalized electrons", giving properties like conductivity, malleability, and ductility (e.g., Cu, Fe).

hydrogen bond

A weak attraction between a hydrogen atom bonded to N, O, or F and a lone pair on another electronegative atom (e.g., between H2O molecules).