【One Question per Day】Safe Zone 03-02-2011

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This post was last edited by ray1513 on 2011-3-2 11:24. When a flammable liquid catches fire, its continuous burning time is less than ＿s. A.5 B. 10 C. 15 D. 30 Note: & p1) Participants receive a reward. 6 2) Please hide your replies; the method to do this is: http://bbs.hcbbs.com/thread-492556-1-1.html. Do not edit the replies after posting them. 13) The answer can be seen after replying.) 4) Also, please do not repeatedly submit answers maliciously. If you make a mistake in your submission, please contact the respective poster or administrator; otherwise, points will be deducted. Answer: A. 　　 When a flammable liquid reaches its flash point, a small amount of flammable vapor at the surface of the liquid mixes with air, and combustion can occur upon exposure to a flame. However, at the flash point temperature, the evaporation rate of the liquid is still relatively slow, so not enough vapor is generated to replace what is lost in combustion; as a result, the flame goes out within 5 seconds, resulting in a brief burst of combustion. When the temperature of a flammable liquid is 1–5°C higher than its flash point temperature, continuous combustion occurs.