IB Chemistry Limiting, Excess, Theoretical and Percentage Yield
IB Chemistry on Limiting, Excess and Percentage Yield.
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Transcript of IB Chemistry on Limiting, Excess and Percentage Yield.
http://lawrencekok.blogspot.com
Prepared by Lawrence Kok
Tutorial on Limiting, Excess and Percentage Yield
Chemical Reaction
Word equation
Chemical equation
Chemical formula
Lead + Potassium → Lead + Potassium Nitrate iodide iodide nitrate
1Pb(NO3)2(aq) + 2KI(aq) → 1PbI2(s) + 2KNO3(aq)
Chemical Reaction
Word equation
Chemical equation
Chemical formula
Reactants – Left side Products – Right side
Conservation MassTotal Mass reactants = Total Mass products
Mole Ratio (stoichiometric ratio)Coefficient in front of reactants/products - moles
Lead + Potassium → Lead + Potassium Nitrate iodide iodide nitrate
1Pb(NO3)2(aq) + 2KI(aq) → 1PbI2(s) + 2KNO3(aq)
1 : 2 → 1 : 2
1Pb(NO3)2(aq) + 2KI(aq) → 1PbI2(s) + 2KNO3(aq)
Chemical Reaction
Word equation
Chemical equation
Chemical formula
Reactants – Left side Products – Right side
Conservation MassTotal Mass reactants = Total Mass products
Mole Ratio (stoichiometric ratio)Coefficient in front of reactants/products - moles
Lead + Potassium → Lead + Potassium Nitrate iodide iodide nitrate
1Pb(NO3)2(aq) + 2KI(aq) → 1PbI2(s) + 2KNO3(aq)
Mass of reactants (PbNO3 + KI) = 15.82
Mass of products (PbI3 + KNO3) = 15.82
AfterBefore
Video on conservation mass1 : 2 → 1 : 2
Chemical reaction • matter is neither created nor destroyed • Undergoes physical and chemical change. • LAW of conservation of mass.
1Pb(NO3)2(aq) + 2KI(aq) → 1PbI2(s) + 2KNO3(aq)
Chemical Reaction
Word equation
CaCO3 (s) + 2HCI → CaCI2(aq) + CO2(g) + H2O(l)
Physical states + symbols
(s) – solid(I) - liqud(g) – gas(aq) – aqueous ∆ - heatingppt –
precipitate/solid↔ - reversible
Calcium + hydrochloric →Calcium + carbon + watercarbonate acid chloride dioxide
Chemical equation
Chemical formula
1CaCO3(s) + 2HCI(aq) → 1CaCI2(aq) + 1CO2(g)
+ 1H2O(l)
1CaCO3(s) + 2HCI(aq) → 1CaCI2(aq) + 1CO2(g)
+ 1H2O(l)
Reactants – Left side Products – Right side
Chemical Reaction
Word equation
CaCO3 (s) + 2HCI → CaCI2(aq) + CO2(g) + H2O(l)
Physical states + symbols
(s) – solid(I) - liqud(g) – gas(aq) – aqueous ∆ - heatingppt –
precipitate/solid↔ - reversible
Calcium + hydrochloric →Calcium + carbon + watercarbonate acid chloride dioxide
Reaction Stoichiometry• Quantitative relationship bet quantities of reactants/ products• Determine quantities/amt (mass, moles, volume) • Predicts how much reactants react and amt products formed• Chemical rxn react in definite ratios
Chemical equation
Chemical formula
1CaCO3(s) + 2HCI(aq) → 1CaCI2(aq) + 1CO2(g)
+ 1H2O(l)
1CaCO3(s) + 2HCI(aq) → 1CaCI2(aq) + 1CO2(g)
+ 1H2O(l)
Reactants – Left side Products – Right side
Conservation MassTotal Mass reactants = Total Mass products
Mole Ratio (stoichiometric ratio)Coefficient in front of reactants/products - moles
1 : 2 → 1 : 1 : 2
Chemical Reaction
Word equation
CaCO3 (s) + 2HCI → CaCI2(aq) + CO2(g) + H2O(l)
Physical states + symbols
(s) – solid(I) - liqud(g) – gas(aq) – aqueous ∆ - heatingppt –
precipitate/solid↔ - reversible
Calcium + hydrochloric →Calcium + carbon + watercarbonate acid chloride dioxide
Reaction Stoichiometry• Quantitative relationship bet quantities of reactants/ products• Determine quantities/amt (mass, moles, volume) • Predicts how much reactants react and amt products formed• Chemical rxn react in definite ratios
Chemical equation
Chemical formula
1CaCO3(s) + 2HCI(aq) → 1CaCI2(aq) + 1CO2(g)
+ 1H2O(l)
1CaCO3(s) + 2HCI(aq) → 1CaCI2(aq) + 1CO2(g)
+ 1H2O(l)
Reactants – Left side Products – Right side
Conservation MassTotal Mass reactants = Total Mass products
Mole Ratio (stoichiometric ratio)Coefficient in front of reactants/products - moles
1 : 2 → 1 : 1 : 2 Video on conservation mass
Before After
1Pb(NO3)2(s) + 2NaI(aq) → 1PbI2(s) + 2NaNO3 (aq)
Balanced Chemical equation
Concept Map
Chemical Reaction
Chemical Equation
Molecular
Equation
CompleteIonic
EquationNet Ionic
Equation
1Pb2+(aq) + 2NO3
-(aq) + 2Na+
(aq) + 2I-(aq) → 1PbI2(s) + 2Na+
(aq)
+ 2NO3-(aq)
1Pb2+(aq) + 2CI-
(aq) → 1PbCI2(s)
Chemical Change
leads to
represented by
1Pb(NO3)2(s) + 2NaI(aq) → 1PbI2(s) + 2NaNO3 (aq)
Balanced Chemical equation
Coefficient• Mole proportion/ratio •(reactant) → (product) 1 : 2 → 1 : 2
Concept Map
Chemical Reaction
Chemical Equation
Molecular
Equation
CompleteIonic
EquationNet Ionic
Equation
1Pb2+(aq) + 2NO3
-(aq) + 2Na+
(aq) + 2I-(aq) → 1PbI2(s) + 2Na+
(aq)
+ 2NO3-(aq)
1Pb2+(aq) + 2CI-
(aq) → 1PbCI2(s)
Chemical Change
leads to
represented by
1Pb(NO3)2(s) + 2NaI(aq) → 1PbI2(s) + 2NaNO3 (aq)
Stoichiometry• Quantitative relationship bet quantities of reactants/products• Determine quantities/amt in (mass, moles, vol) • Predicts amt reactants react and amt products formed• Chemical rxn reacts in definite ratios
Limiting reactant –Use up first- Limit products form- Rxn stop if all used up
Excess reactant – left over- remains behind
Percentage Yield
mass of Actual Yield x 100%mass of Theoretical Yield - Moles /mass product can be used
Theoretical yield- Max amt product form if rxn completed- Stoichiometry ratio / ideal condition- Assume all limiting reagents used up
Actual yield- Amt of product formed experimentally- Less than theoretical yield due to experimental error
1Pb(NO3)2(s) + 2NaI(aq) → 1PbI2(s) + 2NaNO3 (aq)
Balanced Chemical equation
Coefficient• Mole proportion/ratio •(reactant) → (product) 1 : 2 → 1 : 2
Concept Map
Chemical Reaction
Chemical Equation
Molecular
Equation
CompleteIonic
EquationNet Ionic
Equation
1Pb2+(aq) + 2NO3
-(aq) + 2Na+
(aq) + 2I-(aq) → 1PbI2(s) + 2Na+
(aq)
+ 2NO3-(aq)
1Pb2+(aq) + 2CI-
(aq) → 1PbCI2(s)
Chemical Change
leads to
represented by
1Pb(NO3)2(s) + 2NaI(aq) → 1PbI2(s) + 2NaNO3 (aq)
Stoichiometry• Quantitative relationship bet quantities of reactants/products• Determine quantities/amt in (mass, moles, vol) • Predicts amt reactants react and amt products formed• Chemical rxn reacts in definite ratios
Video on concept map above
Limiting reactant –Use up first- Limit products form- Rxn stop if all used up
Excess reactant – left over- remains behind
Percentage Yield
mass of Actual Yield x 100%mass of Theoretical Yield - Moles /mass product can be used
Theoretical yield- Max amt product form if rxn completed- Stoichiometry ratio / ideal condition- Assume all limiting reagents used up
Actual yield- Amt of product formed experimentally- Less than theoretical yield due to experimental error
Limiting and Excess
Limiting reactant – use up first, limits the products form- rxn stops if all used up
Excess reactant – left over, remains behind
Stoichiometric ratio /proportion 1 mol (bun) : 1 mol (hot dog) → 1 mol
+5 5 5
No Excess No limiting
Both hot dog and bun are used up
Limiting and Excess
Limiting reactant – use up first, limits the products form- rxn stops if all used up
Excess reactant – left over, remains behind
Which is limiting and excess ?
How many hot dogs with 6 buns and 3 hot dogs?
Stoichiometric ratio /proportion 1 mol (bun) : 1 mol (hot dog) → 1 mol
+5 5 5
No Excess No limiting
Excess - BunsLimiting - Hot dogs are used up
Both hot dog and bun are used up
+ +
Limiting and Excess
Limiting reactant – use up first, limits the products form- rxn stops if all used up
Excess reactant – left over, remains behind
Which is limiting and excess ?
How many hot dogs with 6 buns and 3 hot dogs?
Stoichiometric ratio /proportion 1 mol (bun) : 1 mol (hot dog) → 1 mol
+5 5 5
+
No Excess No limiting
Excess - BunsLimiting - Hot dogs are used up
Both hot dog and bun are used up
How many burgers with 12 buns and 6 patties?
+ +
Stoichiometric ratio/proportion 2 mol (bun) : 1 mol (burger) → 1 mol
No Excess No limiting
Simulation on limiting/excess
Balanced chemical eqn
Mole of reactants added
Mole ratio/stoichiometry ratio
1Zn (s) + 2HCI (aq) → 1ZnCI2(aq) + 1H2(g)
Mole ratio
1 : 2 → 1: 1
0.30 mol Zn + 0.52 mol HCl added
Moles reactants given, which is limiting and excess ?
11
22
33
Which is limiting and excess ?
1Zn (s) + 2HCI(aq) → 1ZnCI2(aq) + 1H2(g)
1 mol Zn react 2 mol HCI
0.30 mol Zn + 0.52 mol HCl added
0.52 mol HCI0.30 mol Zn
Balanced chemical eqn
Mole of reactants added
Mole ratio/stoichiometry ratio
1Zn (s) + 2HCI (aq) → 1ZnCI2(aq) + 1H2(g)
Mole ratio
1 : 2 → 1: 1
0.30 mol Zn + 0.52 mol HCl added
HCI is limiting
Moles reactants given, which is limiting and excess ?
11
22
33
Which is limiting and excess ?
1st method
1Zn (s) + 2HCI(aq) → 1ZnCI2(aq) + 1H2(g)
1 mol Zn react 2 mol HCI
0.30 mol Zn + 0.52 mol HCl added
1 mol Zn → 2 mol HCI0.30 mol Zn → 2 x 0.30 mol HCI = 0.60 mol HCI needed = 0.52 mol HCI added NOT enough (limiting) = 0.52 (added) < 0.60 (needed)
0.52 mol HCI0.30 mol Zn
Balanced chemical eqn
Mole of reactants added
Mole ratio/stoichiometry ratio
1Zn (s) + 2HCI (aq) → 1ZnCI2(aq) + 1H2(g)
Mole ratio
1 : 2 → 1: 1
0.30 mol Zn + 0.52 mol HCl added
HCI is limiting
Moles reactants given, which is limiting and excess ?
11
22
33
Which is limiting and excess ?
1st method 2nd method
1Zn (s) + 2HCI(aq) → 1ZnCI2(aq) + 1H2(g)
1 mol Zn react 2 mol HCI
0.30 mol Zn + 0.52 mol HCl added
1 mol Zn → 2 mol HCI0.30 mol Zn → 2 x 0.30 mol HCI = 0.60 mol HCI needed = 0.52 mol HCI added NOT enough (limiting) = 0.52 (added) < 0.60 (needed)
0.52 mol HCI0.30 mol Zn
Reactants that produce least amt of product → will be limiting
Assume Zn limiting 1 mol Zn → 1 mol H2 gas0.3 mol Zn → 1 x 0.3 = 0.3 mol H2
Assume HCI limiting 2 mol HCI → 1 mol H2 gas0.52 mol HCI → 1 x 0.52 2 = 0.26 mol H2
HCI is limiting
Simulation on limiting/excess
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
1 : 2 → 1: 2
10.0g Pb(NO3)2 + 10.0g NaI added
Mass reactants given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1 mol Pb(NO3)2 react 2 mol NaI 10.0g Pb(NO3)2 + 10.0g NaI added
0.0302 mol Pb(NO3)2 + 0.0667 mol NaI
1Pb(NO3)2(s) + 2NaI(aq) → 1PbI2(s) + 2NaNO3 (aq)
Mass → Moles Mass = 10.0
RMM 331.2
= 0.0302 mol
Mass = 10.0
RMM 149.9
= 0.0667 mol
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
1 : 2 → 1: 2
10.0g Pb(NO3)2 + 10.0g NaI added
Pb(NO3)2 is limiting
Mass reactants given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1st method
1 mol Pb(NO3)2 react 2 mol NaI 10.0g Pb(NO3)2 + 10.0g NaI added
0.0302 mol Pb(NO3)2 + 0.0667 mol NaI
1 mol Pb(NO3)2 → 2 mol NaI0.0302 mol Pb(NO3)2 → 2 x 0.0302 mol NaI = 0.0604 mol NaI needed = 0.0667 mol NaI add, (excess) = 0.0667 (added) > 0.0604 (needed)
1Pb(NO3)2(s) + 2NaI(aq) → 1PbI2(s) + 2NaNO3 (aq)
Mass → Moles Mass = 10.0
RMM 331.2
= 0.0302 mol
Mass = 10.0
RMM 149.9
= 0.0667 mol
NaI is excess
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
1 : 2 → 1: 2
10.0g Pb(NO3)2 + 10.0g NaI added
Pb(NO3)2 is limiting
Mass reactants given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1st method 2nd method
1 mol Pb(NO3)2 react 2 mol NaI 10.0g Pb(NO3)2 + 10.0g NaI added
0.0302 mol Pb(NO3)2 + 0.0667 mol NaI
1 mol Pb(NO3)2 → 2 mol NaI0.0302 mol Pb(NO3)2 → 2 x 0.0302 mol NaI = 0.0604 mol NaI needed = 0.0667 mol NaI add, (excess) = 0.0667 (added) > 0.0604 (needed)
Reactants that produce least amt of product → will be limiting
Assume Pb(NO3)2 limiting 1 mol Pb(NO3)2→ 1 mol PbI2
0.0302 mol Pb(NO3)2→ 1x0.0302 mol PbI2
= 0.0302 mol PbI2
Assume NaI limiting 2 mol NaI → 1 mol PbI2 0.0667 mol NaI → 1 x 0.0667 2 = 0.0334 mol PbI2
Pb(NO3)2 is limiting
1Pb(NO3)2(s) + 2NaI(aq) → 1PbI2(s) + 2NaNO3 (aq)
Mass → Moles Mass = 10.0
RMM 331.2
= 0.0302 mol
Mass = 10.0
RMM 149.9
= 0.0667 mol
Simulation on limiting/excess
NaI is excess
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
1 : 2 → 1: 1
0.623g Mg + 27.3cm3, 1.25M HCI add
Mass (solid) and Vol/Conc (solution) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1 mol Mg react 2 mol HCI 0.623g Mg + 27.3cm3, 1.25M HCI
0.0256 mol Mg + 0.0341 mol HCI
Mg(s) + 2HCI(aq) → 1MgCI2(aq) + H2 (g)
Mass /Conc → Moles
Mole = Mass RMM= 0.623 = 0.0256 mol 24.31
Mole = M x V 1000= 1.25 x 27.3 = 0.0341 mol 1000
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
1 : 2 → 1: 1
0.623g Mg + 27.3cm3, 1.25M HCI add
HCI is limiting
Mass (solid) and Vol/Conc (solution) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1st method
1 mol Mg react 2 mol HCI 0.623g Mg + 27.3cm3, 1.25M HCI
0.0256 mol Mg + 0.0341 mol HCI
1 mol Mg → 2 mol HCI0.0256 mol Mg → 2 x 0.0512 mol HCI = 0.0512 mol HCI need = 0.0341 mol HCI add, (limit) = 0.0341 (add) < 0.0512 (need)
Mg(s) + 2HCI(aq) → 1MgCI2(aq) + H2 (g)
Mass /Conc → Moles
Mole = Mass RMM= 0.623 = 0.0256 mol 24.31
Mole = M x V 1000= 1.25 x 27.3 = 0.0341 mol 1000
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
1 : 2 → 1: 1
0.623g Mg + 27.3cm3, 1.25M HCI add
HCI is limiting
Mass (solid) and Vol/Conc (solution) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1st method 2nd method
1 mol Mg react 2 mol HCI 0.623g Mg + 27.3cm3, 1.25M HCI
0.0256 mol Mg + 0.0341 mol HCI
1 mol Mg → 2 mol HCI0.0256 mol Mg → 2 x 0.0512 mol HCI = 0.0512 mol HCI need = 0.0341 mol HCI add, (limit) = 0.0341 (add) < 0.0512 (need)
Reactants produce least amt of product → will be limiting
Assume Mg limiting 1 mol Mg→ 1 mol H2
0.0256 mol Mg→ 0.0256mol H2
= 0.0256 mol H2
Assume HCI limiting 2 mol HCI → 1 mol H2 0.0341 mol HCI → 1 x 0.0341 2 = 0.01705 mol H2
HCI is limiting
Mg(s) + 2HCI(aq) → 1MgCI2(aq) + H2 (g)
Mass /Conc → Moles
Mole = Mass RMM= 0.623 = 0.0256 mol 24.31
Mole = M x V 1000= 1.25 x 27.3 = 0.0341 mol 1000
Simulation on limiting/excess
Balanced chemical eqn
Vol/Conc solution added
Mole ratio/stoichiometry ratio Mole ratio
2 : 1 → 1: 1
100ml, 0.2M, NaOH + 50.0ml, 0.5M H2SO4 add
Vol/Conc (solution) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
2 mol NaOH react 1 mol H2SO4
100ml, 0.2M NaOH + 50ml, 0.5M H2SO4
0.02 mol NaOH + 0.025 mol H2SO4
2NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + H2O(l)
Vol/Conc → Moles
Mole = M x V 1000= 0.5 x 50 = 0.025 mol 1000
Mole = M x V 1000= 0.2 x 100 = 0.02 mol 1000
Balanced chemical eqn
Vol/Conc solution added
Mole ratio/stoichiometry ratio Mole ratio
2 : 1 → 1: 1
100ml, 0.2M, NaOH + 50.0ml, 0.5M H2SO4 add
NaOH is limiting
Vol/Conc (solution) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1st method
2 mol NaOH react 1 mol H2SO4
100ml, 0.2M NaOH + 50ml, 0.5M H2SO4
0.02 mol NaOH + 0.025 mol H2SO4
2 mol NaOH → 1 mol H2SO4
0.02 mol NaOH → 1 x 0.02 mol H2SO4
2 = 0.01 mol H2SO4need = 0.025 mol H2SO4add, (excess) = 0.025 (add) > 0.01 (need)
2NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + H2O(l)
Vol/Conc → Moles
Mole = M x V 1000= 0.5 x 50 = 0.025 mol 1000
Mole = M x V 1000= 0.2 x 100 = 0.02 mol 1000
H2SO4 is excess
Balanced chemical eqn
Vol/Conc solution added
Mole ratio/stoichiometry ratio Mole ratio
2 : 1 → 1: 1
100ml, 0.2M, NaOH + 50.0ml, 0.5M H2SO4 add
NaOH is limiting
Vol/Conc (solution) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1st method 2nd method
2 mol NaOH react 1 mol H2SO4
100ml, 0.2M NaOH + 50ml, 0.5M H2SO4
0.02 mol NaOH + 0.025 mol H2SO4
2 mol NaOH → 1 mol H2SO4
0.02 mol NaOH → 1 x 0.02 mol H2SO4
2 = 0.01 mol H2SO4need = 0.025 mol H2SO4add, (excess) = 0.025 (add) > 0.01 (need)
Reactants produce least amt of product → will be limiting
Assume NaOH limiting 2 mol NaOH→ 1 mol H2O0.02 mol NaOH→ 1 x 0.02 mol H2O 2 = 0.01 mol H2O
Assume H2SO4 limiting 1 mol H2SO4 → 1 mol H2O 0.025 mol H2SO4 → 0.025 mol H2O = 0.025 mol H2O
NaOH is limiting
2NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + H2O(l)
Vol/Conc → Moles
Mole = M x V 1000= 0.5 x 50 = 0.025 mol 1000
Mole = M x V 1000= 0.2 x 100 = 0.02 mol 1000
H2SO4 is excess
Click here for animation
2 mol CO react 1 mol O2
45.42L CO + 11.36L O2
2 mol CO + 0.5 mol O2
Balanced chemical eqn
Vol gas added
Mole ratio/stoichiometry ratio Mole ratio
2: 1 → 2
45.42L CO + 11.36L O2 add
Vol (gas) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
2CO(g) + 1O2(g) → 2CO2 (g)
Vol → Moles
Mole = Vol molar vol= 45.42 = 2.0 mol 22.4
Mole = Vol molar vol= 11.36 = 0.5 mol 22.4
2 mol CO react 1 mol O2
45.42L CO + 11.36L O2
2 mol CO + 0.5 mol O2
Balanced chemical eqn
Vol gas added
Mole ratio/stoichiometry ratio Mole ratio
2: 1 → 2
45.42L CO + 11.36L O2 add
O2 is limiting
Vol (gas) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1st method
2 mol CO → 1 mol O2
2 mol CO → 1 mol O2
= 1 mol O2 need = 0.5 mol O2 add, (limit) = 0.5 (add) < 1 (need)
2CO(g) + 1O2(g) → 2CO2 (g)
Vol → Moles
Mole = Vol molar vol= 45.42 = 2.0 mol 22.4
Mole = Vol molar vol= 11.36 = 0.5 mol 22.4
2 mol CO react 1 mol O2
45.42L CO + 11.36L O2
2 mol CO + 0.5 mol O2
Balanced chemical eqn
Vol gas added
Mole ratio/stoichiometry ratio Mole ratio
2: 1 → 2
45.42L CO + 11.36L O2 add
O2 is limiting
Vol (gas) given, which is limiting and excess ?
11
22
33
44
Which is limiting and excess ?
1st method 2nd method
2 mol CO → 1 mol O2
2 mol CO → 1 mol O2
= 1 mol O2 need = 0.5 mol O2 add, (limit) = 0.5 (add) < 1 (need)
Reactants produce least amt of product → will be limiting
Assume CO limiting 2 mol CO→ 2 mol CO2
2 mol CO→ 2 mol CO2
= 2 mol CO2
Assume O2 limiting 1 mol O2 → 2 mol CO2 0.5 mol O2 → 2 x 0.5 mol CO2 = 1 mol CO2 O2 is limiting
2CO(g) + 1O2(g) → 2CO2 (g)
Vol → Moles
Mole = Vol molar vol= 45.42 = 2.0 mol 22.4
Mole = Vol molar vol= 11.36 = 0.5 mol 22.4
Click here for animation
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
2 → 2: 1
1.00g HgO add
Theoretical, Actual and Percentage Yield
11
22
33
44
2HgO(s) → 2Hg(s) + O2(g)
Mass → Moles Mass = 1.00 = 4.6 x 10-3 mol RMM 216.6
Calculate percentage yield O2 , when 1.00g HgO was added. (Actual yield from expt is 0.069g)
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
2 → 2: 1
1.00g HgO add
Theoretical, Actual and Percentage Yield
11
22
33
44
2HgO(s) → 2Hg(s) + O2(g)
Mass → Moles Mass = 1.00 = 4.6 x 10-3 mol RMM 216.6
Theoretical yield- Max amt product form if rxn complete- Stoichiometry ratio/ideal condition - Assume all limiting reagents used up
Actual yield- Amt of product form experimentally- Less than theoretical yield due to experimental error
Percentage Yield
mass of Actual Yield x 100%mass of Theoretical Yield - Moles/mass product can be used
2HgO(s) → 2Hg(s) + O2(g)
Calculate percentage yield O2 , when 1.00g HgO was added. (Actual yield from expt is 0.069g)
Balanced chemical eqn
Mass of reactants added
Mole ratio/stoichiometry ratio Mole ratio
2 → 2: 1
1.00g HgO add
Theoretical, Actual and Percentage Yield
11
22
33
44
Theoretical yield O2 = 0.074g
Actual yield of O2 = 0.069g
Percentage yield = 93.2%
2 mol HgO→ 1 mol O2
4.6 x 10-3 mol HgO→ 4.6 x 10-3 mol O2
2 Mole = 2.23 x 10-3 mol O2
x RMM O2(32)
Mass = 2.23 x 10-3 x 32 Theoretical yield = 0.074g O2
2HgO(s) → 2Hg(s) + O2(g)
Mass → Moles Mass = 1.00 = 4.6 x 10-3 mol RMM 216.6
Simulation on limiting/excess
Theoretical yield- Max amt product form if rxn complete- Stoichiometry ratio/ideal condition - Assume all limiting reagents used up
Actual yield- Amt of product form experimentally- Less than theoretical yield due to experimental error
Percentage Yield
mass of Actual Yield x 100%mass of Theoretical Yield - Moles/mass product can be used
2HgO(s) → 2Hg(s) + O2(g)
Percentage = Mass of Actual Yield x 100% Yield Mass of Theoretical Yield = 0.069g x 100% 0.074gPercentage Yield = 93.2%
Calculate percentage yield O2 , when 1.00g HgO was added. (Actual yield from expt is 0.069g)
Actual yield given = 0.069g O2
Pb(NO3)2 (s) + 2KI(aq) → PbI2(s) + 2KNO3 (aq)
Stoichiometry
Balanced Chemical equation
Coefficient
Mole proportion/ratio
Limiting
Reagent
Excess Reagen
t
Percentage yield
Concept Map
Actual/experimental yield
Theoretical yield
Chemical formula
Pb(NO3)2 (s) + 2KI(aq) → PbI2(s) + 2KNO3 (aq)
Stoichiometry
Balanced Chemical equation
Coefficient
Mole proportion/ratio
Limiting
Reagent
Excess Reagen
t
Percentage yield
Click here for limiting excess notes
Click here for online tutorial
Click here notes
Click here tutorial on austute
Concept Map
Actual/experimental yield
Theoretical yield
Chemical formula
Online tutorial limiting/excess
Click here tutorial on chemwiki Click here tutorial on chemtamu
Acknowledgements
Thanks to source of pictures and video used in this presentation
Thanks to Creative Commons for excellent contribution on licenseshttp://creativecommons.org/licenses/
Prepared by Lawrence Kok
Check out more video tutorials from my site and hope you enjoy this tutorialhttp://lawrencekok.blogspot.com