How should we analyze our data?How should we analyze our data?Get together in your groups and discuss/Do Get together in your groups and discuss/Do Calculations..Calculations..Determine Error that may have effected results Determine Error that may have effected results and and howhow it affected results. it affected results.What might you change next time in your lab?What might you change next time in your lab?What type of calculations do we need?What type of calculations do we need?Calculations that show how you determined the Calculations that show how you determined the amount of reactants needed to create 5.00g of amount of reactants needed to create 5.00g of productproductCalculations that show how precise our data wasCalculations that show how precise our data wasEx: % Error, % Yield (Formula on Handout)Ex: % Error, % Yield (Formula on Handout)

What background information What background information would our reader need?would our reader need?

Reaction Types to predict productsReaction Types to predict products

Solubility RulesSolubility Rules

Balancing EquationsBalancing Equations

How you were able to determine the How you were able to determine the amount of amount of reactants….Stoichiometry…..reactants….Stoichiometry…..

Mole RelationshipsMole Relationships

One mole of atoms, ions, or molecules One mole of atoms, ions, or molecules contains Avogadro’s number of those contains Avogadro’s number of those particlesparticles

One mole of molecules or formula units One mole of molecules or formula units contains Avogadro’s number times the contains Avogadro’s number times the number of atoms or ions of each element in number of atoms or ions of each element in the compoundthe compound

Stoichiometric CalculationsStoichiometric Calculations

The coefficients in the balanced equation The coefficients in the balanced equation give the ratio of give the ratio of molesmoles of reactants and of reactants and productsproducts

Stoichiometric CalculationsStoichiometric CalculationsFrom the mass of From the mass of Substance A you Substance A you can use the ratio of can use the ratio of the coefficients of the coefficients of A and B to A and B to calculate the mass calculate the mass of Substance B of Substance B formed (if it’s a formed (if it’s a product) or used (if product) or used (if it’s a reactant)it’s a reactant)

Stoichiometric CalculationsStoichiometric Calculations

Starting with 1.00 g of CStarting with 1.00 g of C66HH1212OO66… …

we calculate the moles of Cwe calculate the moles of C66HH1212OO66……

use the coefficients to find the moles of use the coefficients to find the moles of HH22O…O…

and then turn the moles of water to gramsand then turn the moles of water to grams

C6H12O6 + 6 O2 6 CO2 + 6 H2O

Lets recap for the Lab ReportLets recap for the Lab Report

Remember that this is just one system of typing Remember that this is just one system of typing chemical reactions. There are other ways of chemical reactions. There are other ways of organizing them, with different names, such as:organizing them, with different names, such as:

Oxidation-reduction (Redox)Oxidation-reduction (Redox)

occurs when electrons are exchanged in a occurs when electrons are exchanged in a reaction. All reaction. All single replacementsingle replacement, , synthesis,synthesis, decompositiondecomposition and and combustioncombustion reactions reactions involve electron exchangeinvolve electron exchange

Acid-Base (a type of double Acid-Base (a type of double replacement)replacement)

occurs when an acid (containing hydrogen occurs when an acid (containing hydrogen ions) reacts with a base (containing ions) reacts with a base (containing hydroxide ions) to produce a salt and waterhydroxide ions) to produce a salt and water

Oxidation-Reduction

Ca(s) + S(s) CaS(s) = Synthesis

What is happening at the atomic level?

Calcium is losing two electrons to sulfur.

In the process, calcium becomes 2+ ion, and sulfur becomes a 2- ion. They are attracted and bond ionically.

Another example:

Aluminum metal replaces copper metal in a solution of copper(II) chloride.

Al(s) + CuCl2(aq) AlCl3(aq) + Cu(s)

= single replacement reaction. Al & Cu trade places. They do so by transferring electrons.

Al loses three electrons

Al Al3+ + 3 e-

Copper gains two electrons

2 e- + Cu2+ Cu

Acid-Base ReactionAcid-Base Reaction

HX(aq) + YOH(aq) HX(aq) + YOH(aq) YX(aq) + H YX(aq) + H22O(l)O(l)

Ex. HNOEx. HNO33(aq) + KOH(aq) (aq) + KOH(aq) KNO KNO33(aq) + H(aq) + H22O(l)O(l)

Net ionic equations are always the same.Net ionic equations are always the same.

HH++(aq) + OH(aq) + OH--(aq) (aq) H H22O(l)O(l)

Oxidation ReductionOxidation Reduction

Like LEO the Lion goes GERLike LEO the Lion goes GER

Gain Electrons ReductionGain Electrons Reduction

Loose Electrons OxidationLoose Electrons Oxidation

Oxidation Reduction ProblemsOxidation Reduction Problems

Mg + HCl > MgClMg + HCl > MgCl22 + H + H22

What is being oxidized? Reduced?What is being oxidized? Reduced?

Charges they start withCharges they start with

Mg 0    H +1 Cl -1    Mg 0    H +1 Cl -1    

Charges they end with  Mg+2 Cl -1 Charges they end with  Mg+2 Cl -1 H  0 H  0 Mg oxidized:Mg 0 - 2e- => Mg Mg oxidized:Mg 0 - 2e- => Mg +2+2

H reduced HH reduced H+1 +1 + 1e- => H 0+ 1e- => H 0

Try this one…Try this one…

2K + F2K + F22 > 2KF > 2KF

What is oxidized? ReducedWhat is oxidized? Reduced

Starting Charge K,0 F,0Starting Charge K,0 F,0

Ending Charges K+, F-Ending Charges K+, F-

F GER… Reduced K LEO OxidizedF GER… Reduced K LEO Oxidized

How about this one..How about this one..

2Fe(s) + 3S(s) > Fe2Fe(s) + 3S(s) > Fe22SS33

Original Charges Fe 0, S,0Ending Charges Fe 3+ S 2-S GER… 0>2- ReducedFe LEO…. 0> 3+ Oxidized