[{"data":1,"prerenderedAt":72},["ShallowReactive",2],{"q-fire-112-1-fire-science-002":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-112-1-火災學概要-002","fire-112-1-fire-science-002",112,1,2,"下列何者屬於準自然發火性物質？",{"A":16,"B":17,"C":18,"D":19},"鈉","赤磷","乙醇","過碘酸","A",null,[],false,"本題考點：自然發火性物質與準自然發火性物質（禁水性物質）之區別。\n【正解理由】自然發火性物質是在常溫空氣中即會自行發熱而起火者，典型為黃磷；準自然發火性物質則是在乾燥空氣中不致立即起火，但一與水或空氣中的濕氣接觸，就產生可燃性氣體並放出大量反應熱而發火者，也就是禁水性物質。鈉屬鹼金屬，遇水劇烈反應生成氫氧化鈉與氫氣，同時放出的反應熱足以引燃所生成的氫氣，符合準自然發火性物質的定義，故選 A。\n【逐項排除】\n(A) 鈉：遇水生成氫氣並放出大量熱，屬禁水性、即準自然發火性物質，貯存時須以煤油等不含水的液體隔絕水氣，為本題應選者。\n(B) 赤磷：即紅磷，發火溫度約攝氏二百六十度，須有外部熱源才著火，屬可燃性固體；容易與黃磷混淆，具自然發火性的是黃磷而非赤磷。\n(C) 乙醇：閃火點約攝氏十三度的水溶性易燃液體（酒精類），須有引火源才點燃，蒸氣與空氣混合達燃燒範圍才有危險，與自然發火無關。\n(D) 過碘酸：含氧的強氧化性物質，本身不燃，作用是在與可燃物混合時提供氧使燃燒加劇，屬氧化性物質而非自然發火性物質。\n【記憶點】黃磷＝自然發火（碰空氣就燒）；鈉、鉀、碳化鈣＝準自然發火（碰水才燒）；赤磷要外部熱源。","這一題的分類語言來自公共危險物品的六類體系：第一類氧化性固體（過碘酸、過氧化鈉、氯酸鹽類等）、第二類易燃固體（赤磷、硫、金屬粉、鎂等）、第三類發火性液體、發火性固體及禁水性物質（黃磷、鈉、鉀、碳化鈣、烷基鋁等）、第四類易燃液體（乙醇屬酒精類）、第五類自反應物質及有機過氧化物、第六類氧化性液體。題目四個選項剛好散落在第一、二、三、四類，把類別記牢就能直接判斷。\n第三類內部還要再切一刀。自然發火性物質重點在「與空氣接觸」：黃磷發火溫度僅攝氏數十度，故須貯存於水中隔絕空氣。禁水性（準自然發火性）物質重點在「與水接觸」，代表反應式為 2Na＋2H₂O→2NaOH＋H₂＋熱，鉀的反應更劇烈，反應熱可直接引燃生成的氫氣；碳化鈣則是 CaC₂＋2H₂O→Ca(OH)₂＋C₂H₂，生成的乙炔燃燒範圍極寬，是典型的遇水危險品。因此同一類物質，貯存策略恰好相反：黃磷放水中，鈉、鉀放煤油中。\n滅火觀念也隨之不同。禁水性物質火災不可用水或水系滅火藥劑（含泡沫），否則等於加燃料；一般以乾砂、膨脹蛭石、專用金屬火災乾粉覆蓋窒熄。這個原則在法規上留下了痕跡：《各類場所消防安全設備設置標準》第 49 條第十二款明定，儲存鋁粉、碳化鈣、磷化鈣、鈉、生石灰、鎂粉、鉀、過氧化鈉等禁水性物質，或其他遇水時將發生危險之化學品的倉庫或房間，得免裝撒水頭——正因為撒水反而製造危險。這一款的物質清單本身就是很好的禁水性物質記憶表。\n易混淆對照與延伸考點：赤磷與黃磷是同素異形體，性質差異卻極大，赤磷因結構穩定而需外部熱源，黃磷則自燃；乙醇這類水溶性易燃液體火災須用水溶性液體用（耐酒精型）泡沫，普通蛋白泡沫會被酒精破壞消泡；氧化性物質本身不燃，考點多在「與可燃物混合的危險」與「不可與還原性物質混存」。命題常把「自然發火」「準自然發火」「引火性」「可燃性」四個詞互換，作答時先問：它是碰空氣就燒、碰水才燒，還是需要火源。",true,[28,31,35,40,44,48],{"webId":29,"stem":30,"number":12,"year":11,"session":12},"fire-112-1-fire-science-001","建築物火災造成人命傷亡的原因，主要是煙與有毒氣體，下列何者為防煙最好的方法？",{"webId":32,"stem":33,"number":34,"year":11,"session":12},"fire-112-1-fire-science-003","下列何者非為火災之特性？",3,{"webId":36,"stem":37,"number":38,"year":39,"session":12},"fire-111-1-fire-science-040","沾有油類之毛巾，集中堆置於塑膠籃而產生自然發火，其原因為下列何者？",40,111,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-112-1-fire-science-004","若空氣中的氧氣體積百分比為 21%，則甲烷完全燃燒的化學理論濃度為多少%？",4,{"webId":45,"stem":46,"number":47,"year":39,"session":12},"fire-111-1-fire-science-039","撕下新購的電視機螢幕保護封膜時遭受靜電，其原因為下列何者？",39,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-112-1-fire-science-005","鄰二甲苯的閃火點為 157℃，若鄰二甲苯於 157℃時的飽和蒸氣壓為 2.0 mmHg，試求其燃燒下限為何？",5,[53,57,61,64,68],{"webId":54,"year":55,"stem":56,"number":13},"fire-114-1-fire-science-002",114,"建築物火災成長過程中有關衰退期的敘述何者錯誤？",{"webId":58,"year":59,"stem":60,"number":13},"fire-113-1-fire-science-002",113,"建築物為防止火焰透過大樓窗口向上層延燒，下列敘述何者正確？",{"webId":62,"year":39,"stem":63,"number":13},"fire-111-1-fire-science-002","有關爆燃與爆轟，下列敘述何者錯誤？",{"webId":65,"year":66,"stem":67,"number":13},"fire-110-1-fire-science-002",110,"依據建築物火災 t2 成長理論，當釋熱率（Q）達到 4 MW 時，需要 300 秒的時間，表示火災成長之速度為下列何者？",{"webId":69,"year":70,"stem":71,"number":13},"fire-109-1-fire-science-002",109,"三個面積分別為 0.20 m ，0.40 m ，0.60 m 之開口相互串聯時，其等效流動面積為何？",1785129966422]