
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: TUESDAY, April 16, 1991                   TAG: 9104160138
SECTION: CURRENT                    PAGE: NRV-8   EDITION: NEW RIVER VALLEY 
SOURCE: 
DATELINE: BLACKSBURG                                LENGTH: Short

TECH TRYING TO BUILD LONGEST SALT BRIDGE

A serpentine of about 2,000 people at Virginia Tech on Wednesday will demonstrate the principle of a common battery on a scale never before attempted. If successful, the attempt will make the "Guiness Book of World Records."

Barbara Bunn, instructor of chemistry, wants 2,000 people to show up on the drill field at 2 p.m. to hold hands to form the world's longest salt bridge.

"A salt bridge is the part of a battery that allows charge to flow between the compartments in the battery," Bunn said.

On one end of the human bridge, Virginia Tech president James McComas will dip a finger into a solution of copper sulfate containing a copper rod. On the other end, Harold McNair, head of chemistry, will put a finger into a solution of zinc sulfate containing a zinc rod. When McComas, McNair and the other people in the line join hands, they will form a salt bridge, allowing the electrical charge to flow between the two connectors through a wire.

Students, faculty, staff and community members may join the experiment. Free refreshments will be available to all who participate. For information, call Bunn at 231-6127.

by CNB