[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-113-1-fire-science-037":3},{"subject":4,"subjectSlug":5,"subjectKicker":6,"subjectShort":7,"question":8,"related":27,"sameNumber":52,"hasEssay":26},"火災學概要","fire-science","火災學 · Fire Science","火災學",{"id":9,"webId":10,"year":11,"session":12,"subject":4,"number":13,"stem":14,"options":15,"answer":20,"answerNote":21,"images":22,"imagesPending":23,"lawTimestamp":11,"explanation":24,"explanationDeep":25,"freq":12,"indexable":26},"fire-113-1-火災學概要-037","fire-113-1-fire-science-037",113,1,37,"主成分為碳酸氫鉀的乾粉滅火藥劑不適用下列何種火災？",{"A":16,"B":17,"C":18,"D":19},"木材火災","電氣火災","汽油火災","酒精火災","A",null,[],false,"本題考點：乾粉滅火藥劑依主成分之分類，與 A 類普通、B 類油類、C 類電氣火災適用範圍之對應。\n【正解理由】主成分為碳酸氫鉀者為第二種乾粉，俗稱紫焰鉀鹽乾粉，其滅火主力是負觸媒作用，靠鉀離子捕捉燃燒鏈鎖反應中的自由基使火焰瞬間中斷，對氣相火焰壓制極快；但藥劑本身缺乏冷卻與滲透能力，無法終止木材、紙類等固體內部持續熱裂解的無焰燃燒，表面火焰撲滅後仍會復燃，因此第二種乾粉的適用範圍僅及於 B、C 兩類火災，故選 A。\n【逐項排除】\n(A) 木材火災屬 A 類普通火災，燃燒深入固體內部並持續產生可燃裂解氣體，需靠水之冷卻與滲透才能徹底熄滅，碳酸氫鉀乾粉不適用。\n(B) 電氣火災屬 C 類，乾粉為不導電之固體微粒，射向帶電設備不致導電，屬適用範圍。\n(C) 汽油火災屬 B 類油類火災，乾粉以負觸媒抑制連鎖反應並覆蓋液面，是本藥劑最典型的適用對象。\n(D) 酒精火災同屬 B 類可燃液體火災，乾粉的化學抑制作用不因液體具水溶性而失效，仍屬適用範圍。\n【記憶點】碳酸氫鉀＝第二種乾粉，滅得了油與電、滅不了木頭；能通吃 A、B、C 三類的只有磷酸二氫銨的第三種乾粉。","乾粉滅火藥劑依主成分共分四種：第一種為碳酸氫鈉，白色，適用 B、C 類；第二種為碳酸氫鉀，紫色，同樣適用 B、C 類，因鉀離子捕捉自由基的效率高於鈉離子，單位重量滅火效能約為第一種的兩倍；第三種為磷酸二氫銨，粉紅或淺黃色，受熱後生成偏磷酸並在固體表面形成熔融黏著被膜，能隔絕氧氣並阻止深層陰燃，因此成為唯一同時適用 A、B、C 三類的乾粉，俗稱多效乾粉；第四種為碳酸氫鉀與尿素之反應物，白色，適用 B、C 類，粒子受熱爆裂可增加作用表面積。\n乾粉的滅火主力是負觸媒，也就是化學抑制作用：燃燒靠氫自由基與氫氧自由基維持鏈鎖反應，鉀、鈉離子在高溫下與這些自由基結合而使鏈鎖中斷，火焰在極短時間內熄滅。這也正是本題的分野所在——負觸媒只作用於氣相火焰，對已深入木材內部的無焰燃燒無能為力；水之所以是 A 類火災的主力藥劑，靠的是高比熱與汽化潛熱帶來的冷卻，以及滲入纖維內部的能力。\n易混淆對照：酒精帶來的難題落在泡沫而不在乾粉。水溶性的醇類會破壞一般泡沫的液膜，須改用抗酒精型泡沫；乾粉以化學抑制滅火，不受水溶性影響，酒精火災仍在其適用範圍之內。\n記憶口訣可寫成「一鈉、二鉀、三磷酸銨、四尿素」，再加一句「只有三號吃三類」。延伸考點：《各類場所消防安全設備設置標準》第 8 條將乾粉滅火設備列為滅火設備種類之一；同標準第 18 條之應設場所表則把乾粉與水霧、泡沫、二氧化碳、惰性氣體、鹵化烴並列，由應設場所就表列設備擇一選擇設置。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-113-1-fire-science-036","依美國防火協會（NFPA）危險物品標示規定，黃色代表何種危險性？",36,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-113-1-fire-science-038","惰性氣體滅火藥劑 IG541 的組成分不包括下列何者？",38,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-113-1-fire-science-035","某鑄造工廠因高溫鋁水洩漏，遇水引發爆炸，此為何種爆炸？",35,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-113-1-fire-science-039","有關於液化石油氣之性質與事故發生之處置原則，下列敘述何者錯誤？",39,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-113-1-fire-science-034","有關熱傳導的敘述，下列何者正確？",34,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-113-1-fire-science-040","有關複燃之敘述，下列何者錯誤？",40,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-112-1-fire-science-037",112,"升高環境溫度對於環氧乙烷的分解爆炸有何影響？",{"webId":58,"year":59,"stem":60,"number":13},"fire-111-1-fire-science-037",111,"存放乙醇倉庫發生火災，下列那一種泡沫滅火劑較適當？",{"webId":62,"year":63,"stem":64,"number":13},"fire-110-1-fire-science-037",110,"有關電氣火災防範對策中，電器設備之正確使用非常重要，在潮濕場所使用電器時，插頭應加裝何種裝置以防止感電發生？",{"webId":66,"year":67,"stem":68,"number":13},"fire-109-1-fire-science-037",109,"D 類火災可使用的滅火劑，何者適合？",{"webId":70,"year":71,"stem":72,"number":13},"fire-108-1-fire-science-037",108,"下列有關 GHS 制度之說明，何者錯誤？",1785129966392]