Unit 4 AP Chemistry - Chemical Reactions Study Guide

What is the difference between a chemical and physical process?

physical = changes in state of matter or physical structure, identity remains the same

chemical change = rearrangement of substances to become a new substance

What are the changes in bond interactions that occur in physical processes and chemical processes?

Bonds in molecules remain in tact in physical changes, but IMFs can shift

Bonds in chemical processes will change to create new substances, as well as form different IMFS

What can be some evidence of a chemical reaction?

Color change, bubbling, solute formation, heat

What are the ALWAYS SOLUBLE ions?

NO3-, K+, Na+, NH4+

What is a net ionic equation?

Shows the ions involved to form a solid/precipitate in a reaction

What is the equivalence point for a titration?

When it neutralizes

When performing a titration, the indicator should change color when the pH is…

7

What occurs typically in a double replacement reaction?

the formation of a solid precipitate (insoluble ionic solid)

What typically occurs in an oxidation-reduction (redox) reaction (Combustion, single-replacement, decomposition)?

Transfer of an electron and change in oxidation number

Basically what you typically would think of for a chemical reaction (color change, gas formation, heat)

What typically occurs in an acid-base reaction?

transfer of a proton aka an H+ ion

What is the net ionic equation for a strong acid and strong base?

H+ + OH- —> H2O (L)

How can you identify a redox reaction?

If you see neutral atom on one side and ions on the other (change in oxidation number, essentially)

What occurs in a combustion reaction?

A reaction with oxygen to produce water and CO2

What happens when a metal undergoes combustion?

Metal oxides form (rust)

According to Bronsted-Lowry theory, acids are

proton donors

According to Bronsted-Lowry theory, bases are

proton acceptors

the species that remains after a proton is donated is called the…

conjugate base

the species formed when a proton is accepted is called?

conjugate acid

Why is H2O special?

It is very neutral and can function as an acid or a base / amphoteric

What is the conjugate base of H2O

OH-

What is the conjugate base of NH4+?

NH3

What is the conjugate base of HS-?

S-2

What is the conjugate base of C5H5Nh+?

C5H5N

What is the conjugate acid of C6H5COO-?

What is the conjugate acid of HC6H5OOH

The oxidation number of any PURE ELEMENT is…?

0

The oxidation number of a MONATOMIC ION equals

the charge on the ion

The oxidation number of FLUORINE in a compound is ALWAYS

-1

Oxygen has an oxidation number of ____ UNLESS if it is combined with FLUORINE, which it will be either ___ or ____ or if it is in peroxide (such as H2O2 or NaO2) which it will be

-2

+1 or +2

-1

Hydrogen has an oxidation number of ____ unless if it is combined with a metal, then it will be ____

+1

-1

In compounds, Group 1 is ____ and Group 2 is____ and Aluminum is ____

+1

+2

+3

The sum of oxiadtion numbers of ALL ATOMS in a NEUTRAL MOLECULE is

0

the sum of the oxidation numbers in a POLYATOMIC ION equals the…

charge of the ion

What is the conjugate acid of HS-?

H2S

What is the conjugate acid of F-

HF

What is the conjugate acid of CO3-?

HCO3-

Is H3O+ an acid or base?

acid

Is CH3COO- a base or an acid?

base

Is H2S an acid or base?

both

is NH3 an acid or base

base

How do you determine the strength of an acid from molecular view of th solution?

Strong acids ionize completely, while weaker acids only partially ionize due to being in an equilibrium state

What patterns exist with conductivity in relation to concentration or strength of an acid or base?

Conductivity is weaker among lower concentrations of base and acids and stronger among acids or bases of higher concentrations. Conductivity is not a main test to indicate strength of an acid or base, unless if their concentrations are the same. Typically stronger acids and bases will have higher conductivity since they will fully dissociate into ions, while weaker ones are in an equilibrium state, meaning not all ions will dissociate

What does the equivalence point mean in a titration?

it is where the solution neutralizes

An redox reaction involves the transfer of…

electrons

an atom that GAINS electrons will have a _____ in its oxidation number

decrease

an atom that LOSES electrons will have an _____ in its oxidation number

increase

The substance whos oxidation number increases is said to be…

oxidized

The substance whose oxidation number decreases in a reaction is said to be

reduced