Chem 10 Flashcards
exothermic
An exothermic process releases heat, causing the temperature of the immediate surroundings to rise.
endothermic
An endothermic process absorbs heat and cools the surroundings.
Open System
Some interactions include
energy or material, which can be transferred into or out of the system
Mass can change
Closed System
Stays true to the laws of conservation
Mass cannot escape or enter
Energy can be transferred into or from the system in the form of heat
Law of conservation of mass
States: Mass cannot be created or destroyed → only change form!
Mass = atoms in the formula
This rule is followed when we do a chemical reactions
synthesis
two → one
A + B → AB
Single Replacement
Compound + single element. Switch with duplicate or - or +
AB + C → AC + B
Decompositon
one → two
AB → A + B
Double Replacement
two compounds switch partners. + and -
AB + CD → AD + CB
Neutralization Reaction
Look for H, OH (will form a compound of water and a salt).
HA + BOH → BA + H20
Combustion Reaction
CHO Method
Makes CO2 + H2O
CxHy + O2 → CO2 + H2O
Define Acid + How to identify
H+ Donator ( Anything + )
Positive
Has H+ to donate
Define Bases
Releases OH- ions
Negative
8-14
Define Salt
a salt is a ionic compound
salt is a result of an acid and base
How many times does pH scale go up (acidic)
10x more acidic each time
What type of ions do all acids form
Hydrogen ions
What is HCI → H2 Cl2
Skeleton
3 types of reactions in an exothermic
A: Reactant
B: Activation energy
C:Product
Define activation energy
The energy needed for the reaction to start
Why does endothermic reaction feel cold
They absorb heat energy from their surroundings. This means that the surroundings of endothermic reactions are colder as a result of the reaction.
Acids and bases can be very …
dangerous + corrosive
pH scale is short form for …
The power of hydrogen
What does the pH scale express
concentration of H+
How to determine pH scale and how not too
Litmus paper is commonly used
Cannot be determined by sight
Acids and bases are often written with subscripts of …
(aq) = aqueous = water
just in water
Acids and bases can conduct ____ because they release ____ in solutions
Acids and bases can conduct electricity because they release ions in solutions
Acids release …
Hydrogen ions H+ (aq)
Bases release …
Hydroxide ions OH- (aq)
Lots of H+ in a “box” means
Lots of OH- in a “box” means
Low pH = lots of H+
High pH = lots of OH-
a solutions cannot have both high [H+ (aq)] and high [OH- (aq)], because…
What is this process called
They cancel each other out and form water
It is called neutralization
H+ + OH- → H2O
What does mass refer to in a chemical reaction.
of atoms in formula
What is an ionic and covalent compound
Ionic bonds : Metal + Non metal
- polyatomic ions
- made of + and -
-charge of compounds always = 0
Covalent bonds : Non metal + non metal
- prefixes
-share valence non-metals
-bond is strong because strong attraction by the shared atoms electrons
Common between both: uses “-ide” for second element
Cation vs Anion
cation :
positive
loses e- ( because they give them away to make them + charged)
anion :
negative
gains e- ( accepts protons, making them negativly charged)
An ion is a ___ atom or molecule
charged
(meaning they do not have equal numbers of electrons and protons)
electrons are found where
orbit, around nucleus
