mole ;-; Flashcards
state symbols:
solid (s), liquid (l), gas (g), ___________ (aq)
aqueous (SPELL IT)
egs of aqueous
acids, alkalis & all soluble salts
SOLUBILITY OF SALTS
salts with grp __ _______, _____________ salts & _________ salts (eg calcium ___________) are all soluble in water
grp 1 cations, ammonium, nitrate, nitrate
SOLUBILITY OF SALTS
all _________ ______ soluble in water except _____________________ & ______________________
btw ______ & _______ halides (grp ___) r ____________ except for _________ (is a halide)
chloride salts, lead (II) chloride (PbCl2), silver chloride (AgCl)
lead, silver, 17, insoluble, flourides
SOLUBILITY OF SALTS
all _________ ______ r soluble in water except _______________________, _______________________ & _______________________
sulfate salts, calcium sulfate (CaSO4), lead (II) sulfate (PbSO4), barium sulfate (BaSO4)
SOLUBILITY OF SALTS
all ____________ _______ INSOLUBLE in water except grp ___ ___________ & _______________________
carbonate salts, 1 carbonates, ammonium carbonate (NH4)CO3
SOLUBILITY OF SALTS
all _________ & ____________ r INSOLUBLE in water except __________________ & ____________________
oxides, hydroxides, grp 1 oxides, grp 1 hydroxides
ionic eqn: simplified chem eqn showing ____ taking part in a __________ & __________ formed, leaving out ____________ ions that don’t take part in reaction
ions, reaction, products, spectator
steps for writing ionic eqn:
1. write balanced ___________ eqn, including _______ _________
2. rewrite it in terms of ______ (dissociate ions of species with ____________ state symbols)
3. cancel out __________ ions (leave all ______, ______ & _______ intact)
4. write the ionic eqn
- chemical, state symbols
- ions, aqueous
- spectator, solids, gases, water
relative atomic mass (Ar)
def: relative atomic mass of element is
ratio of the avg mass of 1 atom of that element to 1/12 of the mass of an atom of carbon-12
Ar can be found
in the periodic table (jus check)
Ar values have ___ ______ & are kept to __ dp
no units, 1
Ar is referring to
a single element (like the value of Ar is only for that element)
isotope def: isotopes r
atoms of the same element with same no. of protons but diff no. of neutrons
relative abundance of isotopes: ____ of isotopes as they’re formed in the naturally occurring element
% percentage
formula to find Ar of an element from isotopes
Ar =
(% x isotope no.) + (% x isotope no.) +…
____________________
100
abundance of Cl-35:
Cl-37:
- 75%
- 25%
def of relative isotopic mass: relative isotopic mass of a particular isotope is
ratio of mass of 1 atom of that isotope to 1/12 the mass of an atom of carbon-12
def of relative molecular mass (Mr): relative molecular mass of a __________ is
molecule, ratio of avg mass of 1 molecule to 1/12 the mass of an atom of carbon-12
Mr is
sum of individual Ar of atoms in molecular formula of the compound
’.’ means
+
relative FORMULA mass (Mr) def: relative formula mass of _______compound is
ionic, ratio of avg mass of 1 formula unit of that compound to 1/12 of mass of an atom of carbon-12
percentage composition by mass of an element in a compound =
(no. of atoms of element x Ar of element
_____________________________
Mr of compound)
whole thing times 100%
avogadro’s constant def:
no. of particles in 1 mole of any substance is a constant
avogadro’s constant:
6.02x10^23
particles is a general term referring to
atoms, molecules, ions
THE MOLE (mol)
is a
unit of the amt of substance
def of mole:
1 mole contains exactly 6.02x10^23 elementary particles
amt (mol) =
no. of particles / 6.02x10^23
no. of particles =
amt (mol) x 6.02x10^23
molar mass of substance is
mass of 1 mole of that substance
molar mass unit:
g/mol
molar mass formula (IMPT) :
amt (mol) = mass (g) / molar mass (g/mol)
molar mass can be calculated using __________ ____________ (eg Ar, Mr)
chemical formula
use of mol ratio in calculations:
1. write
2. calculate
3. find
4. calculate
- balanced chem eqn
- amt of mol of given substance
- mol ratio (thing u know vs thing u dk)
- mol of unknown substance
def of empirical formula: empirical formula of compound shows
simplest ratio of each type of atoms in a compound
def of molecular formula: molecular formula of compound shows
actual no. of atoms in a compound
n x empirical formula =
molecular formula
2 compounds can have the _______ empirical formula tho they have _______ molecular formulas
same, diff
to find empirical formula,
gather all elements tgt, then divide by n
finding empirical formula from elemental composition
- step 1: state mass (g) (assume 100% is 100g)
- step 2: find mol of each
- step 3: divide by smallest mol
- step 4: simplest ratio
finding molecular formula:
empirical formula = Mr (number)
divide Mr by empirical formula value to get n
times empirical formula by n
1 mole of any gas will occupy _______ vol at _______ temp & press
same, same
at s.t.p. (standard temp & press), molar vol is
22.7 dm3/mol
at r.t.p (room temp & press), molar vol is
24.0 dm3/mol
mole ratio =
vol ratio
amt (mol) of gas =
vol (dm3) / molar gas vol (dm3/mol)
amt (mol) of gas =
vol (cm3) / molar gas vol (cm3/mol)
1 dm3 =
1000 cm3
limiting reagent: determines amt of
products formed
at end of a reaction, some reactants used up (____________ reagent) while other reactants may be left over(__________ reagent)
limiting, excess
limiting reagent: one that is
completely used up in reaction
excess reagent: one that is
not completely used up in reaction
if all reactants completely used up, reagents are said to be in
stoichiometric amts
steps for finding limiting reagent:
1. write
2. find ______________ amt (mols) of _______ reactant
3. find __________ amt (mols) for _____ of the reactants –> can tell which is limiting reagent
4. determine _______ _______ between limiting reagent & required _____________
5. solve.
- balanced chem eqn
- available, each
- needed, one
- mole ratio, product
% yield =
(actual mass / theoretical mass) x 100%
for calculating % yield, actual mass can be found _____ ____ & theoretical mass can be calculated using __________ ___________
from qn, limiting reagent
% purity =
(mass of pure / mass of impure) x 100%
for % purity, mass of impure sample can be found
from qn
conc of solution is ____ ___ _______ (in g/mol) contained in given ____ of solution
amt of solute, vol
conc (mol/dm3) =
amt of solute (mol) / vol of solute (dm3)
conc (g/dm3) =
mass of solute (g) / vol of solution (dm3)
relationship between mol/dm3 & g/dm3
molar mass (g/mol) = conc (g/dm3) / conc (mol/dm3)
standard solution: contains _________ amt of solute in _______ _____ of solution
known, given vol
standard solutions can be prepped by adding _________ amt of solute into __________________ _________ & fill it up to mark with appropriate __________ (usually water)
known, volumetric flask, solvent
dilution: process of adding __________ to _________ _____ of solution so as to ________ conc, with amt (in g or mols) of solute _____________ _______ aft dilution
solvent, known vol, lower, remaining same
dilution concept: amt of solute in og solution ___ amt of solute in diluted solution
=
volumetric analysis: quantitative analysis of __________ solution by ___________ fixed vol of this solution with a ___________ solution
unknown, reacting, standard
titration: process involving _________ ____________ of 1 solution (from a burette) to a ________ ______ of another solution (usually in conical flask) until __________________ amts of the 2 solutions have _______________ reacted
gradual addition, fixed vol, stoichiometric, completely
titration: end point usually indicated by suitable ___________ which undergoes __________ __________
indicator, colour change
reactions that can be analysed using titrations:
- acid base reaction (neutralisation)
- redox reaction (transfer of electrons from reducing agent to oxidising agent)
eg of qn that can be asked: pipetting out 25 cm3 out from 250 cm3 of solution
–> 250 cm3 ha x moles
–> 25 cm3 has ____ moles
x/10
calculations in volumetric analysis
1. write chem eqn
2. find _____ of solution1 in 250 cm3
3. find _____ of solution1 in 25 cm3 (by __________ _____)
4. write ____ _______ between solution1 and solution2
5. find amt of ___________
6. find _______ (in _________)of solution2
7. find _______ in ________ of solution2
- amt
- amt, dividing 10
- mol ratio
- solution2
- conc, mol/dm
- conc, g/dm
