General Chemistry 1 Exam 1 Study Guide

pure substance

A sample of matter, either a single element or a single compound, that has definite chemical and physical properties

mixture

A combination of two or more substances that are not chemically combined

elements

A molecule composed of one kind of atom; cannot be broken into simpler units by chemical reactions.

compound

A substance made up of atoms of two or more different elements joined by chemical bonds

physical property

a characteristic of a substance that does not involve a chemical change, such as density, color, or hardness

chemical property

a property of matter that describes a substance's ability to participate in chemical reactions

states of matter

solid: fixed volume and shape
liquid: fixed volume, no fixed shape
gas: no fixed volume or shape

steps of scientific method

observations are made and from those observations hypothesis and laws are made and then are retested by experiments and may be revised, and if enough hypothesis become well established they can form a theory which is then retested and if needed revised

observation

What is seen or measured

hypothesis

A proposed, scientifically testable explanation for an observed phenomenon.

theory

a model for what nature is and why, formed by one or more well established hypothesis

experiment

An investigation done in order to make a discovery or test a hypothesis

scientific law

a brief statement that summarizes past observations and predicts future ones

hypothesis vs law vs observation vs theory

Describes what happens: observation, law
Describes why things happen: hypothesis, theory
Applies to single/small # of events: observation, hypothesis
Applies to al events: law, theory

SI unit for mass

kilogram (kg)

SI unit for length

meter (m)

SI unit for time

second (s)

SI unit for temperature

Kelvin (K)

SI unit for amount of substance

mole (mol)

pico-

10^-12

nano-

10^-9

micro-

10^-6

milli-

10^-3

centi-

10^-2

deci-

10^-1

kilo-

10^3

macro-

10^6

1L=Xgal

0.264

1kg=Xlbs

2.2046

1km=Xmil

0.622

1in=Xcm

2.54

1cm^3=Xml

1

SI unit for volume

cubic meter (m^3)

SI unit for density

kilogram per meter cuber (kg/m^3)

density formula

D=m/v

1 celsius= X kelvin

274.15 (C+273.15)

32 Fahrenheit= X celsius

0 (C=(F-32)*5/9)

percision

how close measurements are to the mean

accuracy

how close measurements are to the actual value or target

formula for cylinder volume

(2πr)H

formula for sphere volume

3/4πr^3

formula for cube volume

L^3

formula for rectangular prism

LWH

law of conservation of mass

the mass of the reactants will be the same as the mass of the products

law of definite proportions

all samples of a given compound have the same ratio of components

law of constant composition

mass % of each element in a compound is fixed

law of multiple proportions

when two elements form more than one compound, the masses of one element that combine with the same mass of the other element are in the ratio of small, whole numbers

mass number

the sum of the number of neutrons and protons in an atomic nucleus

atomic mass

(chemistry) the mass (in atomic mass units) of an isotope of an element

average atomic mass

weighted average of the atomic masses for the isotopes of an element

atomic number

Number of protons

average atomic mass formula

atomic mass=(percent abundance)*(amu)+ percent abundance and masses of other isotopoes

how to solve for % abundance on a mass spectrometer relative scale

(% intensity you wish to find the percent abundance of/ sum of all percent intensities on spectrum) * 100

practice for identifying elements

(https://quizlet.com/64089/elements-of-the-periodic-table-and-their-symbols-flash-cards/)

metals on periodic table

(i will have a periodic table and show you were i think the metals are and you tell me if I am correct from the answer key)(hydrogen is not a metal)

nonmetals on the periodic table

(orange ones are nonmetals)

metalloids on the periodic table

(greens are metalloids)

alkali metals

alkaline earth metals

charge of ions on periodic table

halogens

nobles gases

diatomic gases

(rules of sevens starting from flourine 3 left and 4 down) ( also hydrogen is diatomic)

1 mole

6.022*10^23 things (in this case atoms of an element)

molar mass

the mass of one mole of a pure substance, also the atomic mass in grams

ionic bonds occur between what types of elements?

metals and nonmetals

covalent bonds occur between what kinds of elements

nonmetals and nonmetals

polyatomic ion

several atoms attached together by covalent bonds into one ion, so basically a covalently bound compound with a charge

writing formulas for ionic compounds

1. write metal cation with charge
2. write nonmetal anion with charge
3. charge (without -/+ sign) becomes subscript fro other ion
4. reduce subscripts to smallest whole number ratio
5. check that sum of charges of anions and cations cancel eachother out

how would you name a metal with an invariant charge in a ionic compound

just use the metal name

how would you name a metal with a variable charge in an ionic compound

use the metal name then put the charge in roman numerals in parenthesis next to it
iron(III)

how would you name a nonmetal in an ionic compound

use the stem of the nonmetal name with the suffix -ide
carbon=carbide

when naming a polyatomic ion what would you do if the ion starts with hydrogen

add the hydrogen- perefix and add 1 to the charge

the -ate prefix goes on which polyatomic ions?

oxoanions

what do you do to an -ate ion with one extra oxygen

give in a per- prefix

what do you do to an -ate ion with one less oxygen

change the -ate suffix to -ite

what do you do to an -ate ion with 2 less oxygens

replace the -ate with -ite and give it a hypo- prefix

how do you determine the max number of oxygens in an oxoanion

the center 4 oxoanions and tellurate have a max of 4 oxygens

charge of an oxoanion is

=(x(-2))+main group column number

with x being the number of oxygens

NH4(+)

ammonium

hydrates

ionic compounds with a sepcific number of waters

when writing the name of formulas for covalently bound compounds what would you do

(never use mon- for the first element) (drop last a if name begins with a vowel