Sci 3 Flashcards
What are the five basic types of reactions?
synthesis, decomposition, single replacement, double replacement, combustion
What distinguishes the five basic types of reactions?
pattern of atom rearrangement
What are synthesis reactions also called?
combination reactions
What do double replacement reactions involve?
two ionic compounds in a solution trading ions
Give an example of double replacement reactions
AB + CD to AD +CB
What does the format of a single replacement reaction depend on?
Whether or not the replacement atom is a metal
What are the two single replacement reaction formats?
M + BC to MC + B or N + BC to BN + C
What was the process in which alchemists tried to form gold out of base metals?
transmutation
What field was Johann Baptista van Helmont involved in?
medical chemistry
What was Van Helmont notably opposed to?
alchemy and element transmutation
What cause drove Van Helmont?
understanding disease
What term did Van Helmont introduce?
gas
What seventeenth century physician anticipated the law of conservation of mass?
Van Helmont
What was Van Helmont’s profession?
physician
Who conclusively demonstrated the law of conservation of mass?
Antoine Lavoisier
What five scientists in France and Britain supported van Helmont’s ideas?
Robert Boyle, Joseph Black, Henry Cavendish, Joseph Priestley, and Antoine Lavoisier
What theory made it difficult to determine what caused matter to change form?
phlogiston theory
Did scientists believe that phlogiston could be detected?
no
What question was notable in disproving phlogiston theory?
why air is required for combustion
Who developed a scientific explanation for combustion that refuted phlogiston theory?
Lavoisier
What did Lavoisier heat to form mercury and a gas?
mercury calx
What did Lavoisier discover in his experiment with mercury and calx?
the total mass remained constant when it changed form
What did Lavoisier call the metal calxes?
metal oxides
Who is often called the father of modern chemistry?
Lavoisier
Who discovered that air is composed primarily of oxygen and nitrogen?
Lavoisier
who discovered that water cannot be converted into earth?
Lavoisier
What did Svante Arrhenius believe happened to acids in water?
they break apart to yield a hydrogen ion (+)
What did Arrhenius believe happened to bases in water?
they break apart to yield a hydroxide ion (-)
What could Arrhenius’s theory about acids and bases not explain?
Why molecules like ammonia were basic when they did not contain OH
How do Bronsted and Lawry define an acid?
any reactant that donates a hydrogen ion in a reaction
How do Bronsted and Lawry define a base?
any hydrogen acceptor in a reaction
When NH3 reacts with water, what do water and ammonia act as?
ammonia acts as a base and water acts as an acid
What does ammonia become when it reacts with water?
positive ammonium ion
Why is an ammonia, water reaction solution basic?
ammonia takes a hydrogen from water, forming a hydroxide ion
What can water become when it accepts a hydrogen ion?
A base (hydronium ion)
What is a molecule that can act either as an acid or a base called?
amphoteric
How is pH defined?
the concentration of hydronium ions in units of moles per liter
What is the equation for pH?
-log[hydronium ion]
How is H30+ typically abbreviated?
h+
What is the range of the pH scale?
0-14
A substance with pH below seven is ____
acidic
A basic solution has very little __
hydrogen ions
what is the pH of pure water?
7
Acid-base reactions are a type of ___ replacement reaction
double
what do an acid and base yield?
salt an water
What two molecules react to form NaCl?
HCl and NaOH
What two molecules react to form KBr?
HBr and KOH
What is the process called in which the pH of a solution is measured as acids and bases are mixed together?
titration
What device on the buret allows solutions to be added by drops?
stopcock
When performing a titration, someone might use a _____ flask
erlenmeyer
Is the acid usually in the flask or the buret when performing a titration?
flask
What point is reached when the moles of acid and moles of base are exactly equal to each other?
equivalence point (endpoint of titration)
What do chemists use to identify an equivalence point?
a pH indicator
what alternative to titrations is available?
pH meter
When an acid substance is diprotic, what does it have?
two hydrogens
When an acid substance is triprotic, what does it have?
three hydrogens
What is the process in which salt ions interact with water molecules called?
hydrolysis
What is an anion?
negatively charge ion
What is a cation?
positively charge ion
What is a conjugate acid?
chemical compound formed when an acid donates a proton (H+) to a base
If the anion of the salt reacts with water and produces the conjugate acid of the anion, then the solution will be ___
basic
If the cation of the salt reacts with water to form the conjugate base and a hydrogen ion, then the solution will be ___
acidic
What do anions of weak acids typically form?
basic salts
What type of raction are precipitation reactions?
replacement reactions
In precipitation reactions, what occurrence is notable?
solid precipitate forms
In precipitation reactions, what are the ions that do not form precipitates called?
spectator ions
Look at solubility rules, page 60
Done
What does the precipitation of metal hydroxide depend on?
the concentration of oh
Why do farmers need to add acidic or basic substances to their soils?
to optimize the dissolution of nutrients
One well known contaminant which is also a precipitate is ___
mercury
What type of salt was commonly used in processing photographs?
silver halide salts
what were silver halide salts complexezd with to be precipitated as?
sodium thiosulfate
What is transferred in redox reactions?
electrons
How many valence electrons does sodium have?
1
What are redox reactions useful for?
running batteries
What is the oxidation number for an element?
the number of electrons that need to be added or subtracted in its combined state for it to have the number of electrons in its free, neutral state
What oxidation number do group 1 elements have?
+1
What is the oxidation number of oxygen?
-2
In what cases does H have an oxidation number of -1?
metal hydrides
In what cases does O have an oxidation number of -1?
peroxides
What is the most common example of electroplating?
chrome plating
What is the tendency of an electron to leave or join an atom measured in?
volts
What is the energy measured in volts called?
cell potential
What state is a battery in when it is run down?
equilibrium
What are the the two sides with reactions occurring in a galvanic cell called?
anode and cathode
Who invented the earliest reliable battery?
JF Daniell
Who is most frequently given credit for inventing electroplating?
Luigi Brugnatelli
What did Galvani believe about electricity?
It originated from organisms
Who believed that electricity came from the metals, not the frogs?
Alessandro Volta
Who built the first voltaic pile?
Alessandro Volta
Who discovered electroplating?
Luigi Brugnatelli
What did Brugnatelli first use for electroplating?
gold
When did electroplating become widely used in industry?
1840s
