Incandescent Light Bulb1. Run electric current through very thin piece of Tungsten2. Generates lots of heat along with the light3. inefficient
Compact Fluorescent Bulb
http://www.energystar.gov/index.cfm?c=cfls.pr_cfls_about
1. Produce less heat and more light2. Use less energy3. Use mercury
Choosing the right bulb
a. Energy starb. How much light you want
i. Measured in lumensc. Right shade of light
i. Measured in Kii. Lower temps mean
yellower light
Compact Fluorescent Bulb
http://www.energystar.gov/index.cfm?c=cfls.pr_cfls_about
5. How CFL’s worka. Electric current driven though a tube
containing argon and mercury vapor.b. Generates ultraviolet light that
excites fluorescent coating (phosphor) on the inside if the tube.
c. When phosphor electrons relax again, emit visible light
d. Take more energy initially
CFL’s and mercury4 milligrams per bulb on average.Mercury only an issue when bulbs are broken or to be
disposed of. If the mercury containing powder comes into contact
with anything it must be thrown away.Must recycle old bulbs.CFL’s only produce 30% as much mercury waste as
power plants produce to electricity for incandescent
Seminar QuestionsWhy have some people been reluctant to
adopt CFL’s in their homes and workplaces?What are the pros and cons of CFL’s?
Seminar QuestionsWhy have some people been reluctant to
adopt CFL’s in their homes and workplaces?What are the pros and cons of CFL’s?What are the pros and cons of incandescent
bulbs?
Seminar QuestionsWhy have some people been reluctant to
adopt CFL’s in their homes and workplaces?What are the pros and cons of CFL’s?What are the pros and cons of incandescent
bulbs?How are CFL’s disposed of properly?
Incandescent?
Seminar QuestionsWhy have some people been reluctant to
adopt CFL’s in their homes and workplaces?What are the pros and cons of CFL’s?What are the pros and cons of incandescent
bulbs?How are CFL’s disposed of properly?
Incandescent?Do you believe CFL’s will overtake
Incandescent bulbs in popularity?
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
Sodium is oxidized, going from a 0 to +1 oxidation state.
Iron is reduced, going from a +2 to 0 oxidation state.
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
Carbon is oxidized, going from a –1 to +4 oxidation state.
Oxygen is reduced, going from a 0 to –2 oxidation state.
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
3) 2 PbS + 3 O2 2 SO2 + 2 PbO
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
3) 2 PbS + 3 O2 2 SO2 + 2 PbO
Sulfur is oxidized, going from a –2 to +4 oxidation state.
Oxygen is reduced, going from a 0 to –2 oxidation state.
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
3) 2 PbS + 3 O2 2 SO2 + 2 PbO
4) 2 H2 + O2 2 H2O
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
3) 2 PbS + 3 O2 2 SO2 + 2 PbO
4) 2 H2 + O2 2 H2O
Hydrogen is oxidized, going from a 0 to +1 oxidation state.
Oxygen is reduced, going from a 0 to –2 oxidation state.
Redox PracticeIn each of the following equations, indicate the element that
has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
3) 2 PbS + 3 O2 2 SO2 + 2 PbO
4) 2 H2 + O2 2 H2O
5) Cu + HNO3 CuNO3 + H2
Copper is oxidized, going from a 0 to +1 oxidation state.
Hydrogen is reduced, going from a +1 to 0 oxidation state.
Redox PracticeIn each of the following equations, indicate the element
that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
3) 2 PbS + 3 O2 2 SO2 + 2 PbO
4) 2 H2 + O2 2 H2O
5) Cu + HNO3 CuNO3 + H2
6) AgNO3 + Cu CuNO3 + Ag
Redox Practice In each of the following equations, indicate the element that has been
oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process:
1) 2 Na + FeCl2 2 NaCl + Fe
2) 2 C2H2 + 5 O2 4 CO2 + 2 H2O
3) 2 PbS + 3 O2 2 SO2 + 2 PbO
4) 2 H2 + O2 2 H2O
5) Cu + HNO3 CuNO3 + H2
6) AgNO3 + Cu CuNO3 + Ag
Copper is oxidized, going from a 0 to +1 oxidation state.
Silver is reduced, going from a +1 to 0 oxidation state.
Titration Practice Find the requested quantities in the following problems:
1) If it takes 54 mL of 0.1 M NaOH to neutralize 125 mL of an HCl solution, what is the concentration of the HCl?
Titration Practice Find the requested quantities in the following problems:
1) If it takes 54 mL of 0.1 M NaOH to neutralize 125 mL of an HCl solution, what is the concentration of the HCl?
Because NaOH and HCl are in a 1:1, you can use M1V1 = M2V2
(54 mL NaOH)(0.1 M NaOH) = (125 mL HCl)(M HCl)
M HCl =0.043 M HCl
Titration Practice Find the requested quantities in the following problems:
1) If it takes 54 mL of 0.1 M NaOH to neutralize 125 mL of an HCl solution, what is the concentration of the HCl?
2) If it takes 25 mL of 0.05 M HCl to neutralize 345 mL of NaOH solution, what is the concentration of the NaOH solution?
Titration Practice Find the requested quantities in the following problems:
1) If it takes 54 mL of 0.1 M NaOH to neutralize 125 mL of an HCl solution, what is the concentration of the HCl?
2) If it takes 25 mL of 0.05 M HCl to neutralize 345 mL of NaOH solution, what is the concentration of the NaOH solution?
Because NaOH and HCl are in a 1:1, you can use M1V1 = M2V2
(25 mL HCl)(0.05 M HCl) = (345 mL NaOH)(M NaOH)
M NaOH=0.0036 M NaOH
Titration Practice Find the requested quantities in the following problems:
3) If it takes 50 mL of 0.5 M KOH solution to completely neutralize 125 mL of sulfuric acid solution (H2SO4), what is the concentration of the H2SO4 solution?
KOH + H2SO4 K2SO4 + 2H2O
Titration Practice Find the requested quantities in the following problems:
3) If it takes 50 mL of 0.5 M KOH solution to completely neutralize 125 mL of sulfuric acid solution (H2SO4), what is the concentration of the H2SO4 solution?
KOH + H2SO4 K2SO4 + 2H2O
For problem 3, you need to divide your final answer by two, because H2SO4 is a diprotic acid, meaning that there are two acidic hydrogens that need to be neutralized during the titration. As a result, it takes twice as much base to neutralize it, making the concentration of the acid appear twice as large as it really is.
use M1V1 = M2V2
[(50 mL KOH)(0.5 M KOH)]/2 = (125 mL H2SO4)(M H2SO4)
M H2SO4=0.1 M H2SO4
Titration Practice Find the requested quantities in the following problems:
4) Can I titrate a solution of unknown concentration with another solution of unknown concentration and still get a meaningful answer? Explain your answer in a few sentences.
Titration Practice Find the requested quantities in the following problems:
4) Can I titrate a solution of unknown concentration with another solution of unknown concentration and still get a meaningful answer? Explain your answer in a few sentences. You cannot do a titration without knowing the molarity of at least one of the
substances, because you’d then be solving one equation with two unknowns (the unknowns being M1 and M2).
Titration Practice Find the requested quantities in the following problems:
5) Explain the difference between an endpoint and equivalence point in a titration.
Titration Practice Find the requested quantities in the following problems:
5) Explain the difference between an endpoint and equivalence point in a titration.
Endpoint: When you actually stop doing the titration (usually, this is determined by a color change in an indicator or an indication of pH=7.0 on an electronic pH probe)
Equivalence point: When the solution is exactly neutralized. It’s important to keep in mind that the equivalence point and the endpoint are not exactly the same because indicators don’t change color at exactly 7.0000 pH and pH probes aren’t infinitely accurate. Generally, you can measure the effectiveness of a titration by the closeness of the endpoint to the equivalence point.