Amounts Of Susbtances Flashcards
Define a mole
Amount of a substance that contains the same number of elementary particles as 12g of carbon-12
Avagadro’s number
6.02 X10*23
Valency definition
Ionic charge
Coefficient
Large ratio number in front of a compound
Subscript
Small number at bottom of compound element to show how many atoms of that element there are
Hydrogen carbonate ion HCO3 charge
-1
Phosphate ion charge PO4
-3
What does ide indicate
2 elements bonded
Sodium sulfide
Eg. Na2S
What does age indicate
3 elements bonded
Sodium nitrate
Eg. NaNO3
What does ite indicate
1 less oxygen than ate
Sodium nitrite
NaNO2
How to find ionic equations
Split aq compounds into ions and cancel
Hydroxide ionic equation
H+(aq) + OH-(aq) —> H2O(l)
Carbonate ionic equation
H+(aq) + CO3*2-(aq) —> H2O(l) + CO2(g)
Hydrogen carbonate ionic equation
H+(aq) + HCO3-(aq) —> H2O(l) + CO2(g)
Ammonia ionic equation
H+(aq) + NH3(aq) —> NH4+(aq)
How do ionic compounds dissolve in water
Positive and negative ions separate and become hydrated
Which ionic compounds are soluble (5)
Group 1
Ammonium
Nitrates
Chlorides (not Ag, Pb)
Sulphates (not Ca, Ba, Pb, Sr)
Insoluble ionic compounds (3)
Carbonates
Hydroxides
Oxides
(Not PANNa)
Aqueous solution definition
No. Moles dissolved per dm3 solution
No. Grams dissolved per dm3 solution
What does m represent in the molar gas equation
Space occupied by 1 gaseous mole
Standard conditions
273K/0°C
100KPa
22.4 dm3/mol
Room conditions
293/20°C
100KPa
24 dm3/mol
Gas volume rule
Equal volumes of gas at the same temperature and pressure contain an equal number of molecules
Ideal gas equation
PV = nRT
P - pressure (Pa)
V - volume (m3)
n - moles (mol)
R - gas constant (8.31J/K/mol)
T - temperature (K)
°C —> K
+273
1atm —> Pa
X100,000
Cm3 —> m3
X1,000,000
Dm3 —> m3
/1000
What is atom economy
Measure if the proportion of reactant atoms that become part of the desired product
Atom economy equation
RFM desired products / total RFM of reactants or products X100
Used balanced equation
Advantages of a good atom economy
Efficient, low production cost
More product to sell
Less waste, less disposal cost
Less waste, better for environment
More availability, lower prices
Percentage yield equation
Actual amount of product/ theoretical X100
Reasons for low percentage yield
Reversible reaction
Unexpected reaction/product
Lost in handling/left in apparatus
Not completely pure
Difficult to separate products
