tailieunhanh - Hydrogen Hopes

Even when using a spray booth, spray room or capture unit, sprayers still need to wear air­fed RPE and PPE, and bystanders should be excluded when using isocyanate­based products. The duty is to control exposure to isocyanates to as low as is reasonably practicable. The need for health surveillance still applies. Once spraying has finished, the sprayer should leave the spray booth, room or area wearing the RPE. For isocyanates, re­entry before the clearance time (booth or room) or before 30 minutes (workshop) have elapsed requires air­fed RPE. This always applies. Mist capture and filtration equipment requires annual thorough maintenance, examination and test. . | Scientific American Frontiers . Hydrogen Hopes . Teaching Guide . Hydrogen Fuel - High School. PDF PBS j 7HEDR ANGIER SCIENTIFIC AMERICAN FRONTIERS Hydrogen Hopes saf 1 506 teaching Activity 2 Grades 9-12 Hydrogen Fuel Today we depend mostly on gasoline as a fuel for automobiles. In the future however our reliance may shift to a more common fuel substance hydrogen. As a clean burning fuel hydrogen may be used in new types of internal combustion engines. Of even greater promise is the use of hydrogen in fuel cells. Fuel cells harness chemical reactions to produce electric current. Without the wasteful generation of heat and unwanted pollutants fuel cell technology may soon be powering generations of electric cars. This activity page will offer An introduction to the use of hydrogen as an automobile power source A hands-on activity in generating hydrogen An opportunity to bleach food coloring Getting Hydrogen Whether it is to be used as a clean-burning fuel or as a reactant in fuel cells sources of hydrogen must be identified. The good news is that hydrogen is all around especially in water. Every molecule of water contains two atoms of hydrogen. Freed from the water molecule hydrogen atoms can combine together to form hydrogen gas. In this activity you ll generate hydrogen gas by splitting water in a process called electrolysis. Materials Connecting wires with alligator clips at both ends 400-mL beaker or large jar Scrap cardboard Two 2 graphite pencils With graphite exposed at both ends Tape One 9-volt battery Salt Wax paper Food coloring Scientific American Frontiers . Hydrogen Hopes . Teaching Guide . Hydrogen Fuel - High School. PDF PBS Small beaker Fumehood steps 7-10 CAUTION If students extend the activity to include steps 7-10 remind them of the dangers of inhaling chlorine gas. These steps should only be performed in a fumehood. Teacher note Prior to the activity obtain a set of 2 pencils with eraser ends that have been removed. Use a pencil .