UNIT 1 A Flashcards
Rates of reaction equation
delta Q/delta T
Name 4 things that can impact the rate of a reaction
temperature increase= faster reaction
particle size decrease= faster reaction
concentration increase= faster reaction
addition of catalyst= faster reaction
Name 3 signs of a chemical reaction
change in colour, gas given off, solid being formed
definition of a catalyst
catalysts speed up reactions and remain unchanged
how can the process of a chemical reaction be followed
by measuring the change in concentration, mass or volume
in chemistry do yo use a line of best fit or join the dots on a line graph?
line of best fit
what are the units of average rate dependant on?
the quantity being measured from the y axis and the units of time used in the graph
What does nuclide notation tell us?
the symbol, atomic number and mass of an atom
in nuclide notation placement, where do we find the mass of an atom
ABOVE the symbol
what is the position in atoms of protons, neutrons and electrons
protons/neutrons= inside nucleus electrons= orbiting the nucleus
charge of protons, neutrons and electrons
p= +1 n= no charge e= -1
mass of protons, neutrons and electrons
p= 1 n= 1 e= 0
definition of an isotope
atoms with same atomic number but a different mass number
what is the RAM
relative atomic mass- the average mass of the isotopes of an element
why is the mass number different between isotopes
because they have a different number of neutrons
in electron arrangement what do metals lose and non metals gain to obtain a full outer shell
electrons
why do atoms want a full outer shell of electrons
to become stable like a noble gas
what number of electrons is a full outer shell
8
3 main types of bonding and what elements they represent
covalent- non metals only
ionic- metals and non metals
metallic- metals only
definition of covalent bonding
the attraction between two non metal atoms, where a pair of electrons is shared in the bond
how are the electrons held in a covalent bond
by both nuclei, forming an extremely strong bond
WHAT IS A COVALENT MOLECULE
a group of non metal ions held together by covalent bonds
when do you draw a circle electron cloud diagram
if the element is helium or hydrogen
in electron cloud diagrams does the drawing of the bond include both electrons?
YES
DIATOMIC ELEMENTS ?
HINClBrOF
HYDROGEN, IODINE, NITROGEN, CHLORINE, BROMINE, OXYGEN, FLOURINE
NAME THE 4 DIFFERENT SHAPES OF MOLECULES
linear, angular, trigonal pyramidal, tetrahedral
formula for calculating time in half life
half live multiplied by no. of half lifes
formula for no. half lifes
time divided by 1 half life
formula for half life of a sample
time divided by no. half lifes
moles formula
n=cv
three step calcs steps…
- no. moles 2. mole ratio 3. mass
definition of standard solution
a solution of accurately known concentration
what stops beta emission
ALUMINIUM
What stops alpha emmision
paper
what stops gamma emission
concrete
mass of alpha radiation (shown by nuclide notation)
4
mass of beta radiation
0
mass of gamma radiation
0
charge of alpha radiation
2+
charge of beta radiation
-1
charge of gamma radiation
0
how can unstable nuclei become stable?
by giving out alpha, beta or gamma radiation
half life definition
the time taken for the activity or mass of a radioactive sample to half
I terms of cloud diagrams, what type of bond does oxygen form?
(rarer than most bonds)
a double bond
how many elements in a bond does a tetrahedral shape represent
5
how many elements does a trigonal pyramidal shape represent?
4
what is a covalent network?
an extremely large structure of non metal atoms that extend in 3 dimensions
example of a covalent network structure?
the element carbon (graphite & diamond)
when are ions made
when atoms lose or gain electrons and become pos or neg
what is ionic bonding
the attraction between positive and negative ions
when metals lose electrons, do they form positive or negative ions
(for example: Mg ^2)
POSITIVE
when non metals gain electrons do they form positive or negative ions?
negative
even though they have GAINED electrons they are still negative- still a minus sign!
what structures do ionic compounds exist as?
giant lattice structures
what do substances need to be able to conduct
charged particles which are free to move and carry the electricity
do covalent substances conduct and why?
no, because they have no free, charged particles which can carry electricity
why can graphite conduct unlike all other covalent substances
because it has delocalised electrons whichcan move between carbon atoms
do covalent substances dissolve
not in water but in other liquids such as petrol, yes
what page in data book can you find which ionic substances are soluble
5
why do ionic substances dissolve ?
because water can squeeze between the ions
why do ionic, metallic and covalent networks have a high boiling point b
because they are held by very strong bonds
what is the combustion equatin
hydrocarbon + O2 = energy, CO2, H2O
state whether metallic, ionic and covalent substances are soluble in water?
m= no i= yes c= no
state the MP/BP of molecule and networks
m= low n= high
what is the meaning of the TETRA prefix
4
what is the meaning of the PENTA prefix
5
what does the ionic formula of a compound tell us that other formulas dont?
the valency of the atoms (=the charge)
where do acids come from?
non metal oxides dissolving in water
what is produced when ANY fossil fuels burns (reacts with oxygen)
SO2 and CO2
what do SO2, CO2 AND NO3 all contribute to?
acid rain
descibe the concentration of H+ and OH- ions ins an acidic solutions
H+>OH-
if a metal oxide is soluble what will it dissolve in water to produce?
an alkali
if a metal oxide is insoluble what will happen
the pH will not change
name the three salts we use when naming salts and what they =
hydrochloric= chloride sulfuric= sulphate nitric= nitrate
what three bases can acids react with in neutralisation reactions
metal hydroxides, metal oxides, metal carbonates
what do acids with metal carbonates make
salt+ water+ CO2
when naming salts, what does the first part of the name come from?
the metal of the base
name the three basic steps for neutralisation
1) REACTION- add carbonate until gas is no longer being produced
2) FILTRATION- filter paper to remove excess copper carbonate
#3) EVAPORATION- to remove any water leaving you with the salt
what type of salts are produced by neutralisation reactions? and what reaction would produce the opposite
insoluble salts and precipitation reactions
when will a precipitate form
if there is a combination of metal and non metal ions in a reaction which is insoluble
what is the concentration of an AQUEOUS solution
the mass of the solute dissolved in 1L of water
