Chem Midterms total

Chemistry

The study of matter, its composition, its properties and the changes as it undergoes by reactions.

Matter

Anything that occupies space and has mass.

Sig Figs for Adding and Subtracting

Use the least amount of decimal places.

Sig Figs for Multiplying and Dividing

Least amount of digits after 0 that has decimals

Volume Formula

L x L x L

Density Formula

Mass / Volume

Weight Formula (chem)

Mass x Acceleration

Work Formula

Force x Distance

Kinetic Formula

½ Mass x velocty²

Nano

A measurement unit which is used to understand and control matter at dimensions from 1-100 nanometers.

Accuracy

How close a particular value is to the correct answer.

Precision

The degree of agreement among other measurements.

Law

The summary of the observed behavior.

Theory

An explanation of the behavior and why something occurs.

Hypothesis

A possible explanation for the observations.

Counting Numbers

They’re definition numbers that are assumed to have unlimited sig figs.

Dimensional Analysis

What did Greek Philosophers do in 400 BC?

They proposed that all matter consist of the 4 elements, fire, earth, water, and air

What did the Greek philosopher Democritus find?

The early atomic theory - divisibility of matter

Atomos

Ultimate particles which used shapes as atomic distinctions (or atoms)

What was attempted 2000 years of Alchemy?

Attempting to turn metals into gold.

What was accomplished in 2000 years of Alchemy during “The Hunt”

Preparing mineral acids and isolated elements (ex mercury and sulfur). Elements like mercury and sulfur were discovered.

What occurred during Robert Boyles timeline (1627-1691)?

He quantified the behavior of gasses, found out that elements cannot be broken down to simpler substances, and the list of elements grew.

What did Lavoisier find during his timeline (1743-1794)?

He created the “Law of Conservation of Mass”, where “mass is neither created nor destroyed”

What did Proust find during his timeline (1754-1826)

 He created the “Law of Definite Proportions”, where “a given compound always contains exactly the same proportion of elements by mass”

What did Dalton find during his timeline (1766-1844)?

“The law of multiple proportions”

What was Dalton’s atomic theory (1808)?

The beginning of modern chemistry meaning: “Each element is made up of tiny particles called atoms which are “identical”, “Compounds are formed when atoms combine with each other”, and “Chemical reactions involve the reorganization of atoms”

What are Dalton's Relative Atomic Masses?

Where he prepared the first table of atomic masses based on the relative masses of the elements in known compounds.

What did Gay-Lussac (1778-1850) do?

He measured the volumes of gasses that reacted with each other (at same T,P)

What did Avogadro (1776-1856) do?

He created a hypothesis of “at the same T and P, equal volumes of different gasses contain the same # of particles”

What did Stanisalo Cannizzaro (1826-1910) accepted?

That compounds contained whole # of atoms and that Avogadro’s hypothesis was correct.

What did JJ Thomson (1856-1940) do with Cathode-ray tubes?

He produced a beam of electrons that was deflected with an applied electrical field measuring charge to mass ratio of an electron.

What is the “Plum pudding” model

Where a positive charge cloud has lots of electrons spread out like a muffin.

What did Millikan (1868-1953) find out?

Determined the charge of an electron which is -1.60 x 10^-19 C. He also found the mass of electron to be determined as 9.11 x 10^-31 kg

3 Types of Radiation

Gamma rays (high energy light), Beta particles (high speed electrons), and alpha particles (He^2+ ions)

What are the characteristics of the nucleus?

They are very small and very dense.

What did Rutherford - 1919 predict?

Predicted the existence of the neutral particles to account for the total mass of the atom. 

Why do different atoms have different chemical properties? 

Chemical properties are based on the # and arrangement of the electrons meaning different elements have different # of protons, neutrons and e-.

Atomic Number

# of protons in the nucleus which is also = to # of electrons in a neutral atom.

Isotopes

Atoms with the same atomic # but also have different masses. 

Pure Substances

Atoms combining with other elements

Elements

Pure substances with only one type of atom

Allotropes

Different structural forms of an element.

Compound

Pure substances with two or more atoms

It can also include ionic and covalent bonds

Molecules

A combination of atoms, represented by a chemical formula

Ions

When a natural species gain or loses an electron.

Anions

A negative ion where the # of e- is bigger than the amount of protons.

Cations

A positive ion where the number of protons is bigger than the amount of e-.

Chemical bonds

Force that holds atoms together inside compounds.

Covalent Bonds

Form between non-metallic elements

Ionic Bonds

Due to electrostatic attraction between opposite charged ions.

What do Metallic Atoms form?

Cations

What do Nonmetallic Atoms form?

Anions

Ionic Compounds

Metal + Nonmetal (or two polyatomic ions)

Covalent Compounds

Non-Metallic Elements

Element DNE in nature and made in a Particle Accelerator

Hassium, element 108

Type I Binary Ionic Compounds

A metal forming with a cation.

ex) NaCl = Sodium Chloride

Type II Binary Ionic Compounds

A metal forming with more than one cations

ex) Fe+3, Fe+2

Which Transitional Metal don’t have charges?

Zn 2+, Ag+

Oxy-anions

Anions containing an element with different amount of oxygen atoms

Atoms with small # of O atoms

-ite

ex) (NO2)^- = Nitrite

ex) (SO3)²- = Sulphite

Atoms with big # of O atoms

-ate

ex) (NO)3- = Nitrate

ex) (CO3)2- = Carbonate

Binary Covalent Compound

Compounds between two Non-Metals

Acids

When one ore more H+ is attached to an anion

Acids that doesn’t contain Oxygen

Prefix Hydro-. suffix -ic

ex) HF = Hydrofluoric acid

ex) HCL = Hydrochloric acid

Acids that contain Oxygen

Using -ic or -ous

ex) HNO3 = Nitric

HNO2 = Nitrous

Acids with O and anion name end with -ate

-ic

ex) H2SO4 = sulfuric

Acids with with O and anion name end with -ite

-ous

ex) H2SO3 = sulfurous

Charges for Proton

1+

Charges for Electron

1-

Charges for Neutron

0

Acid Naming: -ate

-ic acid

Acid Naming: -ite

-ous

Acid Naming: -ide

Hydro- … -ic

Polyatomic Naming: A-

-ide

Polyatomic Naming: AO-

Hypo- -ite

Polyatomic Naming: AO2-

-ite

Polyatomic Naming AO3-

-ate

Polyatomic Naming AO4-

Per- … -ate

Atomic Mass

AMU: A unit of mass set relative to a standard mass

Mass Spectrometry

Separates Ions by a mass-to-charge ratio

Relative Atomic Masses

A relative scale of atomic masses (ex. 12C = 12 amu) which can also be used as a comparison of ratio masses.

Mole

A unit of measurement used for counting atoms

Moles to Molecules

1 mole = 6.022137 x 10^23 units of the substance.

Also know as Avogadros Number

Molar Mass

The mass in g of 1 mole of the substance (C = 1 mol/12.011g)

Mass Percent

The mass of the element in a compound as a% of the total mass of the compound.

(mass of an element in 1 mol / mass of 1 mole in the substance ) x 100%

ex) mass of carbon in C2H5OH as a percent

Molecular Formula

 The exact # of atoms in a molecule.

= Molar Mass (periodic table)/ Empirical Mass (Calculations)

ex) C6H12O6 instead of CH2O

Empirical Formula

The formula that shows the smallest whole number ratio of atoms in a compound

Molecular Mass

1 molecule of an atom

Relative Scale of Atomic Masses

Based on Carbon 12

Chemical Equation

Showing what is in a chemical reaction using chemical formulas and symbols to show the reactants and products involved.

Reactants

The substances that undergo a chemical reaction are consumed in the reaction.

The left side of the reaction.

Products

The substances formed after a chemical reaction.

The right side of the reaction.

Chemical Reactions

They involve the rearrangement of the atoms

What is usually Conserved?

The total # of atoms will be conserved

Solution

A combination of two or more substances that exist in a homogeneous mixture.

Solvent

The substance that is present in a greater quantity inside a solution

Solubility

A measure of the amount of a substance that dissolves in a given amount of solvent in a given temperature.

Aqueous Solution

A solution where water is mixed in with acid or the solvent.

Molarity

It represents the amount of molar concentration of the solution.