B1 moles, equations Flashcards
Charge of group 1 ions
1+
Charge of group 2 ions
2+
Charge of group 3 ions
3+
Charge of group 5 ions
3-
Charge of group 6 ions
2-
Charge of group 7 ions
1-
Formula and charge of nitrate
no3-
Formula and charge of carbonate
co3 2-
Formula and charge of sulfate
so4 2-
Formula and charge of hydroxide
oh -
Formula and charge of ammonium
Nh4 +
Formula and charge of zinc
Zn 2+
Formula and charge of silver
ag +
How to write ionic equations
Write balanced symbol equation
Aqueous compounds split, solid remain unchanged
Remove spectator ions
Cancel down
Define Mole
A unit containing 6.02 x10 (23) particles
Define Avagadro’s constant
The number of particles per mole
Equation for the mass of one atom, using avagadro’s constant
Define Empirical Formula
The simplest whole number ratio of atoms of each element present in a compound
Define Molecular Formula
The number and type of atoms of each element in a molecule
Define Anyhdrous
A compound containing no waters of crystallisation
Define Hydrated
A compound containing waters of crystallisation
How to calculate the empirical formula of a compound/waters of crystallisation
Calculate moles of each substance in the compound
Find the simplest whole number ratio
Moles equation, with mass
moles = mass/mr
Moles equation, with volume
moles = vol/24
Moles equation, with concentration
moles = con x vol
Moles equation, with concentration in grams/dm3
Ideal Gas Equation
PV = nRT
What must you always remember when solving a problem using the ideal gas equation
Re-arrange the equation as symbols before solving
Unit of pressure for ideal gas equation, and how to convert from atmospheres
Pascals
1atm = x10(5) pa
Unit for volume in ideal gas equation, and how to convert from other units
meters^3
cm = x10(-6)
dm = x10(-3)
n in ideal gas equation
Moles
Unit for temperature in ideal gas equation, and how to convert
Kelvin
Celsius to kelvin
+273
Equation for percentage yield
Equation for atom economy
Equation for percentage uncertainty
When to multiply uncertainty by 2 when calculating percentage uncertainty
Titres
Mass
Temperature
What is the only gaseous alkali
Ammonia (NH3)
Define an acid
Releases H+ ions in aqueous solutions
Describe the difference between weak and strong acids
Weak acids partially dissociate H+ ions in aqueous solutions
Strong acids fully dissociate H+ ions in aqueous solutions
Define an alkali
Releases OH- in aqueous solutions
Define a salt
The metal ion (X+) has replaced the H+ ion
How many decimal places should be used in titre volumes
2dp
Describe how to obtain a crystal sample
Heat in evaporating basin until crystals start to form around outside
Leave to cool and crystallise
Filter to obtain solid crystals
Dry by dabbing with filter paper
What are concordant results
Results within 0.1cm(^3) of each other
Define Standard Solution
A solution of a known concentration
Describe and explain how to prepare a standard solution
Weigh mass of crystals in beaker on mass balance to 2dp
Dissolve in distilled water
Transfer to 250cm volumetric flask
Rinse beaker and transfer washings to volumetric flask
Make up to mark with more water, so bottom of meniscus is on mark
Use dropping pipette when filling to the mark
Put a stopper on top, and invert several times to mix
if says find mean titre
-use concordant numbers
% error
number of times measured x uncertainly/ value (e.g. mass change)
how could the student modify the experiment to be confident that all water of crystlaition has been removed
heat until constant mass
one modification that would make their method reduce the percentage error of mass of water removed
larger mass or balance to more decimal places
formula of water of cystalisation
crcl3 . 6H20
% by mass
element// mass of mine (found)
mass element/ mass x100
avogadroes rules
always moles x avo
ionic equations need
state symbols
aq + aq –> s
and
balancing
reactants ions
products solid (original value)
states solution
known concentrations
explain how adding exxcess mg affects max temp
max temp same
half energy
half moles
and half volume
explain why students two reactions produce diffenrt volumes of gas
different Mr
moles different
Moles of … > than/….
more moles/ volume of gas
