ʻO ke kemika ka ʻepekema e aʻo ana i nā waiwai, ka haku mele ʻana, a me nā loli o nā mea. Ma ke ʻano he ʻepekema kumu i ke ola o kēlā me kēia lā, he nui nā kānāwai kumu o ke kemika e lawelawe ana ma ke ʻano he kumu mua no ka hoʻomaopopo ʻana i nā mea a me kāna mau hopena. E loiloi kēia ʻatikala i ʻehā mau kānāwai kumu o ke kemika: ke Kānāwai o ka Mālama ʻana i ka Mass, ke Kānāwai o nā Proportions Paʻa, ke Kānāwai o nā Proportions He nui, a me ke Kānāwai o Gay-Lussac.
1. Ke Kānāwai o ka Mālama ʻana i ka Nuipaʻa
ʻO ke Kānāwai o ka Mālama ʻana i ka Mass, i hoʻolauna mua ʻia e Antoine Lavoisier i ka makahiki 1789, ʻōlelo ʻo ia he like ka nuipa o kahi mea ma mua a ma hope o kahi hopena kemika. I nā huaʻōlelo ʻē aʻe, ʻaʻole hiki ke hana ʻia a luku ʻia paha ka nuipa i loko o kahi hopena kemika. He mea koʻikoʻi kēia kumumanaʻo i ka helu ʻana i ka stoichiometry o nā hopena kemika.
laʻana:
Manaʻo mākou he hopena kemika maʻalahi kā mākou:
\[ 2H_2 + O_2 \arrow 2H_2O \]
Inā hoʻomaka kākou me 4 gram o ka hydrogen (H₂) a me 32 gram o ka oxygen (O₂), a laila ʻo ka nuipaʻa o nā mea ma mua o ka hopena he 36 gram. Ma hope o ka hopena, e loaʻa iā kākou he 36 gram o ka wai (H₂O), e hōʻike ana e mau ana ka nuipaʻa holoʻokoʻa.
Ke aʻo mai nei kēia kānāwai iā kākou i kēlā me kēia hopena kemika, pono e like nā nui o nā mea hana a me nā huahana. No laila, i ka wā e hana ai i kahi hoohalike kemika, pono mākou e hōʻoia i kaulike ka hoohalike.
2. Ke Kānāwai o nā Kūlana Mau
Ua kapa ʻia ke Kānāwai o nā Kūlana Paʻa, a i ʻole ke Kānāwai o Proust, ma muli o ka mea nāna i ʻike, ʻo Joseph Proust, nāna i hāpai i ka makahiki 1797. Ua ʻōlelo ʻia ua hana mau ʻia kahi hui kemika me nā mea like ma kahi lakio nui paʻa. ʻO ke ʻano kēia, ʻo kēlā me kēia hāpana wai (H₂O), no ka laʻana, ua hana mau ʻia me ka hydrogen a me ka oxygen ma ka lakio nui like, ma kahi o 1:8.
laʻana:
Inā lawe kākou i ka wai mai kekahi kumu, e ʻike kākou ʻo ka lakio nui o ka hydrogen i ka oxygen he 1:8 mau. Pili kēia i ka wai mai ke kai, nā loko, a i ʻole ka wai ua.
He mea koʻikoʻi kēia kānāwai no ka mea e kōkua ia iā mākou e hoʻomaopopo he paʻa ka hoʻohuihui ʻana o nā hui kemika, me ka nānā ʻole i ko lākou kumu a i ʻole ke ʻano o ka hoʻomākaukau ʻana. Hoʻokumu pū ia i ke kumu no ka hoʻoholo ʻana i nā ʻano kemika o nā hui like ʻole.
3. Ke Kānāwai o nā Hoʻohālikelike Helu
ʻO ke Kānāwai o nā Hoʻohālikelike Helu, i ʻike ʻia e John Dalton i ka hoʻomaka ʻana o ke kenekulia 19, ʻōlelo ʻia inā hiki i ʻelua mau mea ke hana i nā hui he nui ma mua o hoʻokahi, a laila ʻo nā nuipaʻa o kekahi mea i hui pū ʻia me kahi nuipaʻa i hāʻawi ʻia o kekahi mea ʻē aʻe e like me ka lakio o nā helu holoʻokoʻa maʻalahi.
laʻana:
E noʻonoʻo i ke kalapona a me ka oxygen, hiki ke hana i ʻelua mau hui like ʻole: carbon monoxide (CO) a me carbon dioxide (CO₂). I loko o ke kalapona monoxide, ʻo ka lakio o ke kalapona i ka oxygen ma ke kaumaha he 3:4 paha, ʻoiai i loko o ke kalapona dioxide, ʻo ka lakio o ke kalapona i ka oxygen ma ke kaumaha he 3:8 paha. Hōʻike kēia lakio i loko o CO a me CO₂, ʻo ka nui o ka oxygen i hui pū ʻia me kahi nui o ke kalapona i hāʻawi ʻia aia ma ka lakio 4:8, a i ʻole 1:2 paha.
Hāʻawi kēia kānāwai i nā ʻike koʻikoʻi i ke ʻano o ka hui pū ʻana o nā ʻātoma ma nā ʻano like ʻole e hana i nā hui like ʻole, a kākoʻo i ke kumumanaʻo ʻātoma a Dalton e hana ʻia ana ka mea me nā ʻātoma hiki ʻole ke māhelehele ʻia.
4. Ke Kānāwai o Gay-Lussac
ʻO ke kānāwai o Gay-Lussac, i hāpai ʻia e Joseph Louis Gay-Lussac i ka makahiki 1808, ke ʻōlelo nei i loko o kahi hopena kemika, ʻo ka nui o nā kinoea e hana ana a me nā huahana o kā lākou huahana, ke ana ʻia ma ka mahana like a me ke kaomi like, aia ma ka lakio o nā helu holoʻokoʻa maʻalahi. Manaʻo pinepine ʻia kēia kānāwai he hoʻonui ʻana o ke kānāwai o nā ʻāpana paʻa no nā hopena kinoea.
laʻana:
Inā loaʻa iā mākou kahi hopena ma waena o ka hydrogen a me ka oxygen e hana i ka wai, e like me:
\[ 2H_2 (g) + O_2 (g) \arrow 2H_2O (g) \]
No laila, ʻelua mau nui o ke kinoea hydrogen e hana me hoʻokahi nui o ke kinoea oxygen e hana i ʻelua mau nui o ke kinoea wai (mahana). Hōʻike kēia i ka lakio o nā nui o nā kinoea e hana ana he helu holoʻokoʻa maʻalahi (2:1:2).
He mea nui loa kēia kānāwai i ke kemika kinoea a kōkua i ka wehewehe ʻana pehea e launa pū ai nā kinoea i nā hopena kemika. Kōkua pū ia i ka hoʻoholo ʻana i ka nui molar o ke kinoea a me ke kumumanaʻo o ka mole i ke kemika.
Ka hopena
ʻO kēia mau kānāwai kumu ʻehā o ke kemika—ʻo ke Kānāwai o ka Mālama ʻana i ka Mass, ke Kānāwai o nā Proportions Paʻa, ke Kānāwai o nā Proportions He nui, a me ke Kānāwai o Gay-Lussac—he mau kia koʻikoʻi i ko mākou ʻike ʻana i nā hopena kemika a me ke ʻano o nā mea. ʻAʻole lākou e hāʻawi wale i kahi ʻōnaehana no ka wānana ʻana i ka hopena o nā hopena kemika akā kōkua pū kekahi i nā helu helu pololei i loko o ka hale hana kemika.
Ma ka hoʻomaopopo ʻana a me ka hoʻopili ʻana i kēia mau kānāwai, hiki iā kākou ke hoʻomaopopo maikaʻi i ke ao a puni kākou, mai nā kaʻina hana ʻoihana nui a hiki i nā hanana kūlohelohe o kēlā me kēia lā. ʻO lākou ke kumu no nā ʻike a me nā hana hou he nui i ka kemika, e hoʻomau nei i ka hoʻokuke ʻana i nā palena o ka ʻike kanaka.
