hola aniani
ʻO nā hopena o ka hola he mau loli ka hopena (no ka laʻana, he hoʻololi i ke kala) ʻaʻole ʻike koke ʻia, akā ma hope o kekahi manawa ma hope o ka hui ʻana i nā reagents. Aia kekahi mau hopena e ʻae iā ʻoe e ʻike i ka hopena i nā manawa he nui. Ma ka hoʻohālikelike me ka "wāki kemika" hiki ke kapa ʻia lākou he "hourglass kemikal". ʻAʻole paʻakikī ka loaʻa ʻana o nā reagents no kekahi o nā hoʻokolohua.
No ka ho'āʻo e hoʻohana mākou i ka magnesium oxide, MgO, 3-4% hydrochloric acid, HClaq (ʻakika concentrated, hoʻoheheʻe ʻia me ka wai 1:9) a i ʻole ka vīnega meaʻai (6-10% solution o ka acetic acid CH3COOH). Inā ʻaʻohe magnesium oxide, e hoʻololi maikaʻi ʻia nā lāʻau lapaʻau e hakakā ai i ka acidity a me ka heartburn - ʻo kekahi o nā mea hana he magnesium hydroxide (Huli ʻo MgO i kēia pūhui ma lalo o nā kūlana hopena).
Ke kuleana no ka hoʻololi kala i ka wā o ka hopena ʻulaʻula bromthymol - Huli melemele ka mea hōʻailona i loko o ka waiʻawaʻawa a aneane polū.
No ke aniani 100 cm3 e ninini i 1-2 teaspoon o ka magnesium oxide (kiʻi 1) aiʻole e ninini ma kahi o 10 cm3 hoʻomākaukau me ka magnesium hydroxide. A laila e hoʻonui i ka 20-30 cm.3 wai (kiʻi 2) a hoʻohui i kekahi mau kulu o ka hōʻailona (kiʻi 3). Hoʻohui i nā mea i loko o ke aniani ʻulaʻula (kiʻi 4) a laila ninini i kekahi mau kenimika3 waiʻakika (kiʻi 5). Huli melemele ka hui ʻana o ke aniani (kiʻi 6), akā ma hope o kekahi manawa, lilo hou ia i polū (kiʻi 7). Ke hoʻohui nei i kahi ʻāpana ʻē aʻe o ka hoʻonā waika, ʻike hou mākou i kahi hoʻololi kala (kiʻi 8 a me 9). Hiki ke hana hou i ke kaapuni.
Ua hana ʻia kēia mau ʻano i loko o ka beaker:
1. Hoʻopili ka Magnesium oxide me ka wai e hana i ka hydroxide o kēia metala:
MgO + H2O → Mg(OH)2
ʻAʻole hiki ke hoʻoheheʻe ʻia ka hui i ka wai (ma kahi o 0,01 g no 1 dm3), akā he kumu ikaika ia a ua lawa ka ʻike o nā ion hydroxide e kala i ka mea hōʻike.
2. ʻO ka hopena o ka magnesium hydroxide me ka hoʻohui ʻana i ka waika hydrochloric:
Mg(OH)2 + 2HCl → MgCl2 + 2H2O
alakaʻi i ka neutralization o nā Mg (OH) a pau i hoʻoheheʻe ʻia i ka wai2. ʻOi aku ka HClaq hoʻololi i ke kaiapuni i acidic, hiki iā mākou ke ʻike ma ka hoʻololi ʻana i ke kala o ka mea hōʻailona i melemele.
3. Hoʻopili kekahi ʻāpana o ka magnesium oxide me ka wai (hoohalike 1.) a hoʻopau i ka waika nui (hoohalike 2.). Lilo hou ka hopena i ka alkaline a lilo ka mea kuhikuhi i polū. Hoʻopau hou ʻia ka pōʻai.
ʻO ka hoʻololi ʻana i ka ʻike e hoʻololi i ka hōʻailona i hoʻohana ʻia, e alakaʻi ana i nā hopena kala like ʻole. I ka lua o ka ho'āʻo ʻana, ma kahi o ka bromthymol blue, e hoʻohana mākou i ka phenolphthalein (ʻaʻohe kala i loko o kahi solution acid, raspberry i kahi solution alkaline). Hoʻomākaukau mākou i kahi hoʻokuʻu o ka magnesium oxide i loko o ka wai (ka mea i kapa ʻia ka waiū o magnesia), e like me ka hoʻokolohua mua. E hoʻohui i kekahi mau kulu o ka solution phenolphthalein (kiʻi 10) a hoʻoulu i nā mea i loko o ke aniani. Ma hope o ka hoʻohui ʻana i kekahi3 ʻakika hydrochloric (kiʻi 11) ʻaʻole waihoʻoluʻu ka hui ʻana (kiʻi 12). Ma ka hoʻoulu ʻana i nā mea i nā manawa a pau, hiki i kekahi ke nānā i nā ʻano like ʻole: ka hoʻololi ʻana i ka waihoʻoluʻu i ka ʻulaʻula, a ma hope o ka hoʻohui ʻana i kahi ʻāpana o ka waikawa, ka discoloration o nā mea o ka moku (kiʻi 13, 14, 15).
Hoʻomaka ka hopena ma ke ʻano like me ka hoʻāʻo mua. Ma kekahi ʻaoʻao, ʻo ka hoʻohana ʻana i kahi hōʻailona ʻokoʻa ka hopena i nā hopena kala like ʻole. Aneane hiki ke hoʻohana ʻia kahi hōʻailona pH ma ka hoʻokolohua.
ʻO ka hola kiʻimika ʻāpana I:
ʻO ka hola aniani ʻāpana I
ʻO ka hola aniani ʻāpana II:
ʻO ka ʻāpana Hoʻomaʻamaʻa Kimia XNUMX
