Nā nīnau hoʻohālike a me ke kūkākūkā ʻana o nā Alkanes
He mau hui hydrocarbon maʻalahi nā Alkanes nona nā pilina hoʻokahi ma waena o nā ʻātoma kalapona a me ka hydrogen. Ua kapa ʻia hoʻi lākou he paraffins a he mau kaulahao kalapona saturated. ʻO ke ʻano nui o nā alkanes ʻo ko lākou inertness, ʻo ia ke kumu e hoʻohana pinepine ʻia ai lākou ma ke ʻano he wahie a me nā lubricants. Ma kēia ʻatikala, e kūkākūkā mākou i kekahi mau pilikia hoʻohālike a me kā lākou mau hoʻonā e pili ana i nā alkanes.
Hoʻolauna i nā Alkanes
Hiki ke hōʻike ʻia nā Alkanes e ke ʻano maʻamau \(C_nH_{2n+2}\), kahi \(n\) ka helu o nā ʻātoma kalapona. ʻO ka alkane maʻalahi loa ʻo ia ka methane (\(CH_4\)) me hoʻokahi ʻātoma kalapona. Ma hope o kēia e ka ethane (\(C_2H_6\)), propane (\(C_3H_8\)), a pēlā aku. Ma hope o ka IUPAC (International Union of Pure and Applied Chemistry) nomenclature nā inoa e hoʻohana ana i ka hopena '-ane'.
Nā Waiwai Kino o nā Alkanes
– Ke kūlana kino: ʻO ka nui o nā ʻātoma kalapona i loko o ke kaulahao, ʻo ke kiʻekiʻe o nā kiko heheʻe a me ka paila. No ka laʻana, he mau kinoea ka methane, ethane, a me ka propane i ka mahana o ka lumi, ʻoiai he mau wai nā alkanes nui (e.g., octane).
- Solubility: ʻAʻole hiki ke hoʻoheheʻe ʻia nā Alkanes i ka wai akā hiki ke hoʻoheheʻe ʻia i nā mea hoʻoheheʻe nonpolar ʻē aʻe ma muli o ko lākou ʻano hydrophobic.
- Ka hana hou: ʻAʻole i like ka pane ʻana o nā Alkanes me nā hydrocarbons ʻē aʻe ma muli o ko lākou mau pilina paʻa ikaika.
Nā Hana Koʻikoʻi o nā Alkanes
- Ke kuni ʻana: Hiki i nā Alkanes ke puhi piha i ka carbon dioxide a me ka wai, a i ʻole ke kuni piha ʻole e hana ana i ka carbon monoxide a me ka wai.
– Halogenation: Hiki i nā Alkanes ke hana me nā halogens (e.g., chlorine a bromine paha) ma lalo o kekahi mau kūlana e hana i nā alkyl halides.
E nānā kākou i kekahi mau nīnau hoʻohālike a me kā lākou mau kūkākūkā e hoʻomaopopo maikaʻi i nā manaʻo i luna.
Laʻana Nīnau 1: Ke Kapa ʻana i nā Alkanes
Nīnau
E hāʻawi i ka inoa IUPAC no ka hui aʻe:
1. \( CH_3-CH_2-CH_3 \)
2. \( CH_3-CH_2-CH_2-CH_2-CH_3 \)
3. \( CH_3-CH_2-CH_2-CH_2-CH_3-CH_2-CH_3 \)
Pahana
1. ʻO ka hui me ke ʻano \( CH_3-CH_2-CH_3 \) he propane. ʻO Propane ka inoa IUPAC no kēia hui.
2. ʻO ka hui me ke ʻano \(CH_3-CH_2-CH_2-CH_2-CH_3 \) he pentane. ʻO Pentane ka inoa IUPAC no kēia hui.
3. ʻO ka hui me ke ʻano hana \(CH_3-CH_2-CH_2-CH_2-CH_3-CH_2-CH_3 \) he heptane. ʻO Heptane ka inoa IUPAC no kēia hui.
Wehewehe
I ke kapa ʻana i nā alkanes, hiki ke hahai ʻia ʻelua mau lula nui:
1. E ʻike i ke kaulahao kalapona lōʻihi loa ma ke ʻano he kaulahao nui.
2. E kapa iā ia e like me ka helu o nā ʻātoma kalapona i loko o ke kaulahao (met-, et-, prop-, but-, a pēlā aku), a ukali ʻia e ka pākuʻi hope -ane.
Laʻana Nīnau 2: Nā Isomers
Nīnau
E kākau a e kapa i nā ʻano isomeric no ka butane (\(C_4H_{10}\)).
Pahana
ʻElua mau isomers hoʻonohonoho o ka Butane:
1. n-Butane:
ʻAno: \( CH_3-CH_2-CH_2-CH_3 \)
Inoa IUPAC: n-Butane
2. ʻIsobutane (Methylpropane):
Kapili:
".
CH3
|
CH3-C-CH3
|
H
".
Inoa IUPAC: 2-Methylpropane
Wehewehe
ʻO nā isomers he mau hui me ke ʻano molekala like akā nā ʻano like ʻole. No ka butane (\(C_4H_{10}\)), loaʻa iā mākou ʻelua mau ʻano hiki:
– he kaulahao kalapona pololei ko n-Butane.
– He lālā (methyl) ko Isobutane ma ka lua o ke kalapona.
Laʻana Nīnau 3: Ke kuni ʻana o nā Alkanes
Nīnau
E kākau i nā hopena kuni piha a piha ʻole no ka propane (\(C_3H_8\)).
Pahana
1. Ka Puhi Kūpono Loa:
Pane: \( C_3H_8 + 5O_2 \rightarrow 3CO_2 + 4H_2O \)
2. Ka Puhi ʻAʻole i Hoʻopau ʻia:
- Hoʻopuka i ke kalapona monoxide:
Pane: \( C_3H_8 + 3.5O_2 \rightarrow 3CO + 4H_2O \)
– Hoʻopuka i ke kalapona paʻa (soot):
Pane: \( C_3H_8 + 2O_2 \rightarrow 3C + 4H_2O \)
Wehewehe
I ke kuni piha ʻana, hana nā alkanes me ka oxygen lawa e hana i ke kalapona ʻokikene a me ka wai. ʻO ke kuni piha ʻole, ma muli o ka nele o ka oxygen, hana i ke kalapona monoxide a i ʻole ke kalapona paʻa.
Laʻana Nīnau 4: Nā Hana Hoʻololi i loko o nā Alkanes
Nīnau
E kākau i ka hoʻohālikelike hopena no ka halogenation o ka methane me ka chlorine a e kapa i ka huahana hopena.
Pahana
Ka hopena pani no ka methane me ka chlorine:
\[ CH_4 + Cl_2 \rightarrow CH_3Cl + HCl \] (i ke alo o ke kukui UV)
ʻO nā huahana i loaʻa he methyl chloride (\(CH_3Cl\)) a me ka hydrochloric acid (\(HCl\)).
Wehewehe
ʻO ka Halogenation kahi hopena e pani ʻia ai hoʻokahi a ʻoi aku paha nā ʻātoma hydrogen i loko o kahi alkane e nā ʻātoma halogen. I kēia hihia, hana ka methane me ka chlorine, kahi e pani ʻia ai hoʻokahi ʻātoma hydrogen e kahi ʻātoma chlorine, a koi ʻia ke kukui UV ma ke ʻano he mea hoʻoulu.
Laʻana Nīnau 5: Nā Formula Empirical a me Molecular
Nīnau
Hāʻawi ʻia kahi hui alkane me ka haku mele nui o 82,76% kalapona a me 17,24% hydrogen, e hoʻoholo i nā haʻilula empirical a me nā molekala no ka alkane inā ʻo kona nuipa molar he 58 g/mol.
Pahana
1. E helu i nā mole o kēlā me kēia mea ma muli o ka nuipa ʻātoma.
– C: \( \left(\frac{82,76}{12}\right) = 6,896 \)
– H: \( \left(\frac{17,24}{1}\right) = 17,24 \)
2. E hoʻomaʻamaʻa i ka hoʻohālikelike e hoʻomaʻalahi:
– Lākiō piha: \( \left(\frac{6,896}{6,896}\right) = 1 \)
– Ka lakio H/C: \( \left(\frac{17,24}{6,896}\right) = 2,5 \)
3. Hoʻololi i ka lakio: \[ C_{2}\left(\frac{2,5 \cdot (2)}{2}\right)H_{5} = C_{4}H_{10}\]
4. ʻO ke ʻano hana empirical he \(C_4H_{10}\) kūlike me kahi alkane (58 g/mol).
Wehewehe
Ma ka hahai ʻana i kēia mau ʻanuʻu, loaʻa iā mākou nā ʻano empirical a me nā molekala o nā alkanes i hoʻonohonoho ʻia ma muli o nā nuipa atomika pili a me ke kaulike nuipa holoʻokoʻa.
Ka hopena
He mea nui ka hoʻomaopopo ʻana i nā alkanes i ke kemika organik kumu. Ma o nā ʻano hoʻohālike a me nā kūkākūkā like ʻole, ua uhi mākou i ke ʻano o ka inoa ʻana i nā alkanes, ka hoʻomaopopo ʻana i ka isomerism, nā hopena puhi, ka hoʻololi ʻana, a me ka hoʻoholo ʻana i nā ʻano empirical a me nā molekala o nā alkanes. ʻO ka hoʻomaopopo ʻana i kēia mau manaʻo e kōkua iā ʻoe e hoʻomākaukau no nā noi like ʻole a me nā pilikia e pili ana me nā hydrocarbons saturated i ke ola o kēlā me kēia lā a me ka ʻoihana.
