80 likes | 271 Vues
LEYTON SIXTH FORM COLLEGE. CHEMISTRY SAFETY PROJECT 2003-2004. Combustion of alcohols using spirit burners can be hazardous. As part of the chemistry safety project a demonstration of what can go wrong will be prepared by the end of the summer term. Spirit Burners the problems .
E N D
LEYTON SIXTH FORM COLLEGE CHEMISTRY SAFETY PROJECT 2003-2004
Combustion of alcohols using spirit burners can be hazardous. As part of the chemistry safety project a demonstration of what can go wrong will be prepared by the end of the summer term
Spirit Burners the problems • Many designs have a capacity of over 100 mls • Many spirit burners on the market are sold for aromatherapy and as table decorations • The tops on some burners do not fit properly • Some burners are made from thin glass • Quality control may be a problem
Spirit Burners on the market (note the best burner is on the far right).
Preparing the spirit burners • Use a small funnel to fill a spirit burner as the openings on the burners are narrow and it is easy to spill highly inflammable liquid • Fill the spirit burner more than half full. This ensures that there will not be an explosive mixture of air and alcohol vapour • Check the wick holders are not chipped. The tops must be loose so that they can be filled but not so loose that they can fall out
Wicks • Replace a wick with one of the same diameter- explosions occur when the flame travels down a narrow wick and ignites the alcohol/air mixture in the burner. • A small explosion can be generated by using a wick which is too narrow for the hole particularly with methanol
Combustion of Methanol • Methanol is TOXIC by inhalation, skin absorption and if swallowed; it is HIGHLY FLAMMABLE but the level of methanol in the atmosphere of the laboratory will be minimal during the use of the burners • Methanol is the most volatile alcohol and for an explosion to occur a mixture of air and alcohol vapour is required-the explosion range is between 7% and 37%
Demonstration A demonstration video showing what can go wrong and how to prevent explosions happening using methanol and spirit burners will be a project for after the exams in June