Chem I Chapter 1, 2, 3 (Exam 1 Material)

All SI Units

Kilogram, Meter, Second, Kelvin, Ampere, Mol

KMS KAM

Finding Empirical Formula Given Mass

1. Convert grams to moles

2. Divide everything by smallest mole # to get subscript # for each element

Note: If dividing gives a non-whole number, multiply everything by a number that will make everything a whole #

Finding Empirical Formula Given Percent Composition

1. Convert #% to #g (assume out of 100g)

2. Convert grams to moles

3. Identify smallest # of moles and divide everything by it

• If result = whole #, we’re done = subscripts

• If a result isn’t whole #, multiply everything by a # that makes everything a whole #

Finding Empirical Formula from Molecular Formula

Take of GCF from subscripts of molecular formula

Finding Molecular Formula

molar mass of compound / molar mass of Empirical Formula

whatever this result is, multiply all subscripts of Empirical Formula by it

Empirical Formula Definition

Formula with the simplest, general, nonspecific ratio of atoms present

Molecular Formula Definition

Specific Formula/ratio of atoms present

Subscripts can be simplified to find Empirical Formula

Converting from Fahrenheit TO Celsius

(Fahrenheit - 32) / 1.80

Converting from Celsius TO Fahrenheit

1.80 (Celsius) + 32

Naming Acids Containing Oxygen

1. Identify polyatomic ion and its ending

   • If end with -ATE, change to -IC and end with ACID

   • If end with -ITE, change to -OUS and end with ACID

How to Name Compunds w/ Metals and Nonmetals that Aren’t Transition Metals

Use regular naming with 2nd element being named like an anion

How to Name Compounds w/ Transition Metals

Use roman numerals to specify the charge of the transition metal

• the charge of the transition metal will cancel out the charge of the other element in the compound

How to Name Compounds w/ Two Nonmetals

Use prefixes

• mono never used for first element, but can be used for second

How to Name Compounds with Polyatomic Ions

Use regular name of first element + the full polyatomic ion name after

Physical Properties Examples

Color

Density

Texture

Phase

Hardness

Conduction

Temperature

Smell

Chemical Properties Examples

Flammability

Rusting

Combustibility

Smoke Observed

Acidity

Light Given Off

Digestion

Drop of Liquid Goes Down Flask

Something is partially consumed

Every measurement has what?

They have a random error

Accuracy

Ability to match a specific value

Precision

Ability to get measurements all the same/how well you can group data

Random Error

A type of error that you can’t fix because don’t know why it occurs

• combat by doing experiment many times

• happens in every measurement

Systemic Error

A type of error that can be corrected

Mass Percent Formula

molar mass of element / molar mass of compound

What does [Element] - # Mean?

That [Element]’s mass is #

• mass = protons + neutrons

Density Formula

mass / volume

How to Find Average Atomic Mass Given Mass and Abundance %

Average Atomic Mass = (abundance %₁ x atomic mass₁) + (abundance %₂ x atomic mass₂) + …

Which Periodic Table Group are Diatomic Elements?

Group 17 aka Halogens

What is a Molecular Element?

An element that exists as two or more atoms

• i.e. N₂

Mega (M)

1,000,000

Kilo (k)

1000

Deci (d)

0.1

Centi (c)

0.01

Milli (m)

0.001

Micro (µ)

0.000001

Nano (n)

0.000000001

Tetra

4

Hepta

7

Penta

5