[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-110-1-fire-science-009":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-110-1-火災學概要-009","fire-110-1-fire-science-009",110,1,9,"碳化鈣（CaC2，俗稱電石）常用於水果的催熟，屬於公共危險物品，遇水會起激烈反應產生下列何種可燃性氣體？",{"A":16,"B":17,"C":18,"D":19},"氫氣","乙烷","乙烯","乙炔","D",null,[],false,"本題考點：碳化鈣（電石）屬禁水性物質，其水解反應所生成的可燃性氣體種類。\n【正解理由】碳化鈣遇水立即水解，反應式為 CaC₂ + 2H₂O → Ca(OH)₂ + C₂H₂↑，生成氫氧化鈣與乙炔。乙炔的燃燒範圍極寬（約 2.5 至 81 vol%），舊式電石燈即利用此反應取火照明，也因此電石必須密封防潮貯存，故選 D。\n【逐項排除】\n(A) 氫氣是鹼金屬（鈉、鉀）或金屬氫化物（如氫化鈉）遇水的產物，例如 2Na + 2H₂O → 2NaOH + H₂↑；碳化鈣含碳，水解時氫會與碳結合成烴類，不會單獨放出氫氣。\n(B) 乙烷（C₂H₆）為飽和烴，碳原子須各接三個氫，水解只能替乙炔根補上兩個氫，無從加氫飽和成乙烷。\n(C) 乙烯（C₂H₄）含碳碳雙鍵，而碳化鈣中的碳以乙炔根 C₂²⁻ 三鍵形式存在，水解不會斷鍵重排成雙鍵；工業上乙烯多來自石油裂解。\n(D) 乙炔（C₂H₂）正是乙炔根接上兩個氫的直接產物，敘述正確。\n【記憶點】電石加水等於乙炔，碳化鈣火場注水只會火上加油。","碳化鈣工業上由生石灰與焦炭在電弧爐中約 2,000 ℃ 反應製得（CaO + 3C → CaC₂ + CO↑），故俗稱電石。它是離子型碳化物，晶格中以 Ca²⁺ 與乙炔根 C₂²⁻ 組成，C₂²⁻ 是極強的鹼，一遇水便奪取質子形成 H—C≡C—H，這就是水解必得乙炔的結構理由。理論上每公斤純碳化鈣可產生約 0.35 立方公尺乙炔，反應同時放熱，密閉容器內極易因升溫與升壓而破裂。\n乙炔本身的危險性有三層：一是燃燒範圍寬達 2.5 至 81 vol%，稍有洩漏即落入可燃區；二是自燃溫度約 305 ℃、最小引燃能量僅約 0.02 mJ，靜電即足以點燃；三是乙炔為吸熱化合物，加壓超過約 2 kgf\u002Fcm² 時可在無氧狀態下自行分解爆炸，故鋼瓶內須以丙酮吸附於多孔物質中貯存。乙炔另會與銅、銀生成具敏感性的乙炔化物，含銅量高的合金因而不用於乙炔管線。\n禁水性物質的水解產物是本科高頻對照題，宜整理成表記憶：鈉、鉀與氫化鈉遇水產生氫氣；碳化鈣產生乙炔；碳化鋁（Al₄C₃）產生甲烷；磷化鈣（Ca₃P₂）產生磷化氫；過氧化鈉則放出氧氣並大量放熱。這類物質在公共危險物品分類中歸於發火性液體、發火性固體及禁水性物質，其火災的抑制原理是隔絕水分並以乾砂、膨脹蛭石等惰性材料覆蓋，注水或使用水系泡沫反而助長反應。\n延伸考點包括：問哪一種物質遇水生成甲烷、問乙炔的燃燒上限、問電石庫房為何要求乾燥通風，答題主軸都回到同一個結構事實——碳化物的碳以何種形式存在，決定水解後得到哪一種烴。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-110-1-fire-science-008","根據美國防火協會危險物品標示規定，將危險類別記載於菱形方塊上，其中「有害健康毒性」以何種顏色表示？",8,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-110-1-fire-science-010","甲基乙基酮過氧化物（MEKPO）常用於聚合物的生產，加熱至 100 ℃時會發生爆炸，此化合物屬於那一類公共危險物品？",10,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-110-1-fire-science-007","己烷在閃火點時的飽和蒸氣壓為 9.12 mmHg，根據 Burgess-Wheeler 定理其燃燒熱約為多少 kcal\u002Fmole？",7,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-110-1-fire-science-011","輻射熱是造成木造建築物延燒原因之一，下列何者正確？",11,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-110-1-fire-science-006","阿里山發生森林火災，已知火災當天的相對濕度為 60.0%，前一天相對濕度為 50.0%，再前一天相對濕度為 40.0%，試求火災當天的實效濕度？",6,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-110-1-fire-science-012","根據 NFPA265 對閃燃現象（flashover）之定義，下列敘述何者錯誤？",12,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-113-1-fire-science-009",113,"在工業上若發生沸騰液體氣化膨脹爆炸（BLEVE）常會造成極大災害，下列那一個不屬於其發生的機制或原因？",{"webId":58,"year":59,"stem":60,"number":13},"fire-112-1-fire-science-009",112,"下列何者屬於我國法定公共危險物品中的易燃固體？",{"webId":62,"year":63,"stem":64,"number":13},"fire-111-1-fire-science-009",111,"有關粉塵爆炸的敘述，下列何者錯誤？",{"webId":66,"year":67,"stem":68,"number":13},"fire-108-1-fire-science-009",108,"就同一種可燃性粉塵而言，下列何種措施有助於降低發生粉塵爆炸的危險性？",{"webId":70,"year":71,"stem":72,"number":13},"fire-107-1-fire-science-009",107,"要做好火災預防工作，從理論觀點上，可由火災預防之「3E 政策」著手，下列敘述何者不屬於「3E 政策」項目？",1785129966985]