Download Chem 106 Week 10.2017

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Chem 106: Class/ Lab Week 10 Sign in: Roster @ front of lab Pick up handouts (2) For today’s experiment Work with the lab partner(s) who set up fermenta;on with you Chem 106: Class/ Lab Week 10 Turn in Today 1.  Chemical ReacEons (Course/ Lab Manual pp. 49-­‐51) 2.  ReacEons, Balancing, Stoichiometry Worksheet (Course/ Lab Manual pp. 65-­‐67) 3.  Stoichiometry / LimiEng Reactant / Ideal Gas Law (Completed Handout) Have stamped before leaving lab: DisEllaEon (Course/ Lab Manual pg. 46) Hydrochloric acid + sodium hydrogen carbonate
Chem 106: Class/ Lab 1 HCl(aq) + 1 NaHCO3 (s)
_ ___ + _ ___ + _ ___
Week 10: Week 11 is Spring Break Due Week #12 1.  Completed FermentaEon Report form (Course/ Lab Manual pg. 46) 2.  FermentaEon Post Lab Ques. [Handout: Individually done] White = hydrogen
Red = oxygen
Gray = carbon
Green = chlorine
Purple = sodium
Write a complete balanced
chemical equation for the
reaction by adding products and
stoichiometric coefficients from
the above reactants.
Hydrochloric acid + sodium hydrogen carbonate
Hydrochloric acid + sodium hydrogen carbonate
1 HCl(aq) + 1 NaHCO3 (s)
2 HCl(aq) + 2 NaHCO3 (s)
1 CO2(g) + 1 H2O(l) + 1 NaCl(aq)
Handout
--
White = hydrogen
Red = oxygen
Gray = carbon
Green = chlorine
Purple = sodium
Write a complete balanced
chemical equation for the
reaction by adding products and
stoichiometric coefficients from
the above reactants.
White = hydrogen
Red = oxygen
Gray = carbon
Green = chlorine
Purple = sodium
Draw a balanced molecular
representation for all of the products of
the reaction using the following key.
(One water molecule is shown.)

Carbon
Hydrogen 
Oxygen 
Chlorine
Sodium
✪
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Hydrochloric acid + sodium hydrogen carbonate
1 HCl(aq) + 1 NaHCO3 (s)
Hydrochloric acid + sodium hydrogen carbonate
2 HCl(aq) + 2 NaHCO3 (s)
In the previous case, all of the reactant
molecules react to produce products
and none remain. In this case some
reactant remains. Draw the molecule
that remains above.
White = hydrogen
Red = oxygen
Gray = carbon
Green = chlorine
Purple = sodium

Carbon
Hydrogen 
Oxygen 
Chlorine
Sodium
✪
Hydrochloric acid + sodium hydrogen carbonate
__ HCl(aq) + _ NaHCO3 (s)
_ ___ + _ ___ + _ ___
In the first case, all of the reactant
molecules react to produce products
and none remain. In this case some
reactant remains. Draw the molecule
that remains above.
White = hydrogen
Red = oxygen
Gray = carbon
Green = chlorine
Purple = sodium

Carbon
Hydrogen 
Oxygen 
Chlorine
Sodium
✪
HCl(aq) + NaHCO3 (s)
Trial 2: An unknown concentration of HCl was added to
the flasks using the same amounts of NaHCO3 used in
trial 1.
Examine the image above and select the correct statement below.
Follow the Demo and complete the Handout
http://chemconnections.org/general/chem106/106assign.html#CO2
HCl(aq) + NaHCO3 (s)
Trial 2: An unknown concentration of HCl was added to
the flasks using the same amounts of NaHCO3 used in
trial 1.
A)  NaHCO3 is the limiting reagent in the yellow and blue.
B)  HCl is definitely not the limiting reagent in all three cases.
C)  Equal numbers of moles of HCl and NaHCO3 may have reacted
in green.
D)  NaHCO3 is definitely the limiting reagent in all three cases.
Energy: Heat: Enthalpy (ΔH)
Examine the image above and select the correct statement below.
A)  NaHCO3 is the limiting reagent in the yellow and blue.
B)  HCl is definitely not the limiting reagent in all three cases.
C)  Equal numbers of moles of HCl and NaHCO3 may have reacted
in green.
D)  NaHCO3 is definitely the limiting reagent in all three cases.
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Distillation
Energy Diagrams
http://chemconnections.org/general/movies/htmlswf/oil-refining.swf
Oil Refining:
http://science.howstuffworks.com/oil-refining4.htm
Energy Diagrams
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https://www.youtube.com/watch?v=rdCsbZf1_Ng
Kinetics: Rate & TIME
(What is a second?)
How fast is a reaction?
Calcula;ons DisEllaEon (Course/ Lab Manual pg. 46) 4
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Example
Example
24.55 g
24.55 g
52.2 mL
52.2 mL
0.990 g/mL
0.990 g/mL
4.5 %
Theoretical Yield Calculation
? g (theoretical)
24.55 g
Chem 106: Class/ Lab 4
Week 10 Molar mass =
342.3 g /mol ? mol sucrose = 24.55 g / 342.3 g /mol = 0.07172 mol Molar mass =
46.07 g /mol ? mol C2H5OH = 4 x mol sucrose
= 0.2869 mol ? g (theoretical) = mol C2H5OH x 46.07 g/mol
= 13.22 g
__________________
? g (actual) = [4.5 % ,that is: 4.5/100] x 52.2 mL x 0.990 g/mL
= 2.33g
% Yield = g (actual) / g (theoretical) x 100
Today’s experiment: Comple;on of Chemical ReacEons/ FermentaEon/ DisEllaEon Due & stamped Today DisEllaEon (Course/ Lab Manual pg. 46) = 17.6 %
Chem 106: Class/ Lab Week #12 A^er Spring Break 1) TitraEon of Vinegar QuanEtaEve Acid-­‐Base ReacEon (NeutralizaEon) Using a standard NaOH aqueous soluEon Determining the % Ace;c Acid in vinegar samples 2) Exam 2 Refer to the Course Calendar prac;ce ques;ons 2 pages handwrifen notes, which are to be turned in, plus Periodic Table allowed Chem 106: Class/ Lab Week #10 Pick up dis;lla;on kit from the stockroom. Assemble as shown. Complete instruc;ons in Lab Manual. Have page 46 stamped before leaving lab. DisEllaEon (Course/ Lab Manual pg. 46) Turn in Week #12 aSer Spring Break Plus: FermentaEon Post Lab on-­‐line Ques. Handout http://chemconnections.org/general/chem120/ethanol-ques-106.html
[Handout: Individually done] 5
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