Alkane

Alkane sī páu-hô-ê hydrocarbon, in hun-chú lāi-té-ê só͘-ū carbon (C) kah hydrogen (H) gôan-chú chi-kan ê hòa-ha̍k-kiān lóng-sī tan-kiān. Alkane ê hòa-ha̍k-sek siá-chòe C_nH_2n+2. Alkane ê chú-iàu lâi-gôan sī chio̍h-iû kah thian-jiân-khì. Ta̍k-ê carbon gôan-chú ū 4-ê hoà-ha̍k-kiān (C-H ia̍h-sī C-C kiān), só͘-ū-ê hydrogen gôan-chú lóng kah chi̍t-ê carbon gôan-chú kiat-ha̍p (H-C kiān). Kiat-kò͘ siōng kán-tan-ê alkane sī methane (CH₄). Tī alkane ka-cho̍k lāi-té, carbon ê sò͘-liōng pēng-bô hān-chè. Alkane ê hóan-èng-sèng bô kóng chin kiông. Só͘-ū-ê alkane lóng bô-sek bô-bī.

Páu-hô-ê hydrocarbon khó-lêng sī:

• Ti̍t-sòaⁿ (hoà-ha̍k-sek C_nH_2n+2)
• Hun-chi (hoà-ha̍k-sek C_nH_2n+2, n > 3)
• Khôan-chōng (hoà-ha̍k-sek C_nH_2n, n > 2)

 

Nā-sī carbon ê sò͘-liōng chhiau-kòe 3, alkane tō ū kò͘-chō ī-sèng-thé ê chûn-chāi. Chi̍t-ê alkane siōng kán-tan-ê ī-sèng-thé sī ti̍t-sòaⁿ bô hun-chi ê hit-ê, chit-khóan ī-sèng-thé hō-chòe "n-alkane" ("n" tāi-piáu eng-bûn ê "normal", "it-poaⁿ" ê ì-sù). Carbon ê sò͘-liōng nā jú chōe, ī-sèng-thé ê sò͘-liōng mā cheng-ka jú kín.

• C₁: chí-ū methane, bô ī-sèng-thé.
• C₂: chí-ū ethane, bô ī-sèng-thé.
• C₃: chí-ū propane, bô ī-sèng-thé.
• C₄: ū 2-ê ī-sèng-thé, n-butane kah isobutane.
• C₅: ū 3-ê ī-sèng-thé, pentane, isopentane, kah neopentane.
• C₆: ū 5-ê ī-sèng-thé, hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, kah 2,3-dimethylbutane.
• C₁₂: ū 355-ê ī-sèng-thé.
• C₃₂: ū 27,711,253,769-ê ī-sèng-thé.
• C₆₀: ū 22,158,734,535,770,411,074,184-ê ī-sèng-thé, put-kò chin-chōe pēng-bô ún-tēng.

Hun-chi-ê alkane iáu-ū khó-lêng ū chhiú-sèng.

Ti̍t-sòaⁿ alkane

Hun-chi alkane

Piáu-keh

Alkane	Hoà-ha̍k-sek	Hut-tiám [°C]	Iûⁿ-tiám [°C]	Bi̍t-tō͘ [g·cm−3](20°C)	Bô͘-hêng-tô
Methane	CH4	−162	−182	khì-thé
Ethane	C2H6	−89	−183	khì-thé
Propane	C3H8	−42	−188	khì-thé
Butane	C4H10	0	−138	khì-thé
Pentane	C5H12	36	−130	0.626 (e̍k-thé)
Hexane	C6H14	69	−95	0.659 (e̍k-thé)
Heptane	C7H16	98	−91	0.684 (e̍k-thé)
Octane	C8H18	126	−57	0.703 (e̍k-thé)
Nonane	C9H20	151	−54	0.718 (e̍k-thé)
Decane	C10H22	174	−30	0.730 (e̍k-thé)
Undecane	C11H24	196	−26	0.740 (e̍k-thé)
Dodecane	C12H26	216	−10	0.749 (e̍k-thé)
Hexadecane	C16H34	287	18	0.773 (e̍k-thé)
Icosane	C20H42	343	37	kò͘-thé
Triacontane	C30H62	450	66	kò͘-thé
Tetracontane	C40H82	525	82	kò͘-thé
Pentacontane	C50H102	575	91	kò͘-thé
Hexacontane	C60H122	625	100	kò͘-thé

Hut-tiám

 

Alkane hun-chú chi-kan lóng ū van der Waals le̍k ê chò-iōng; chit-khóan chò-iōng nā-sī jú kiông, alkane ê hut-tiám tō jú kôaiⁿ. Phòaⁿ-tòan van der Waals le̍k ê kiông-jio̍k, ū nn̄g-chióng hong-sek:

• Hun-chú ióng-iú ê tiān-chú sò͘-liōng. Chit-ê sò͘-liōng ē tòe Alkane hun-chú-liōng ê cheng-ka lâi cheng-ka.
• Hun-chú ê piáu-bīn-chek tōa-sè.

Tī piau-chún chōng-hóng hā, CH₄ kàu C₄H₁₀ sī khì-thé, C₅H₁₂ kàu C₁₇H₃₆ sī e̍k-thé, C₁₈H₃₈ chi-āu tō lóng-sī kò͘-thé. In-ūi hun-chú ê tāng-liōng sī éng-hióng alkane hut-tiám tōa-sè ê chú-iàu in-sò͘, in-chhú alkane hun-chú ê hut-tiám hām hun-chú-liōng ê tōa-sè ū sòaⁿ-sèng koan-hē. Iû piⁿ-á ê chhu-sè-tô͘ ē-sái khòaⁿ-chhut: múi cheng-ka chi̍t-ê carbon, alkane hun-chú ê hut-tiám tō ē cheng-ka 20 kàu 30°C.

Ti̍t-liān alkane ê hut-tiám lóng pí ū hun-chi ê kôaiⁿ, in-ūi hun-chi ē kiám-chió hun-chú chi-kan ê chiap-chhiok piáu-bīn-chek, khì éng-hióng-tio̍h alkane hun-chú chi-kan ê van der Waals le̍k. Pí-lūn-kóng, pí-kàu n-butane kah isobutane (2-methylpropane), in-ê hut-tiám hun-pia̍t sī 0°C kah -12°C.

Iûⁿ-tiám

Alkane ê iûⁿ-tiám chham in-ê hut-tiám ū kâng-khóan-ê kiâⁿ-hiòng, gôan-in mā kah téng-bīn kóng-tio̍h-ê kâng-khóan. Tī pa̍t-hāng gōa-chāi tiâu-kiāⁿ lóng sio-kâng ê chōng-hóng chi-hā, hun-chú khah tōa, iûⁿ-tiám chū-jiân chiū ē khah tōa. Put-kò, iûⁿ-tiám chham hut-tiám ê kiâⁿ-hiòng ū chi̍t-ê bô-kâng-ê só͘-chāi. Ùi bīn-téng-ê kiâⁿ-hiòng-tô͘ (lâm-sek ê sòaⁿ), ē-sái hoat-hiān khia-sò͘ alkane ê iûⁿ-tiám kiâⁿ-hiòng pí siang-sò͘-ê khah kē tām-po̍h-á; che sī in-ūi siang-sò͘ alkane ê kiat-kò͘ pí khia-sò͘-ê khah ún-kò͘, só͘-í chiū su-iàu khah kôaiⁿ-ê lêng-liōng (un-tō͘) lâi tùi kò͘-thé chiâⁿ-chòe e̍k-thé.