pāpāhua

base (chemistry)

WHAKAMĀRAMA

He rōpū pūhui matū, he kōaro ōna āhuatanga matū i ērā o te waikawa. Ko tā te pāpāhua he whakangū i te waikawa, mā te tango i ngā katote hauwai (H⁺) wātea o roto i te waikawa. He kaha ake ngā pāpāhua kohuke, pērā i te konukura ōkai (CuO), i ngā pāpāhua whaiwaro. Ko te waipāhua hei ingoa mō te pāpāhua ka memeha ki rō wai. Ko te kukūtanga o tētahi mehanga pāpāhua tētahi āhuatanga matua e kaha ai, e ngoikore ai rānei tōna pāpāhuatanga. Hei tauira o te whakamahinga o te pāpāhua, ko te konupora waihā (Mg(OH)₂) i roto i te pire tokopā, me te konutai waihā (NaOH) i ngā wai horoi umu.

A class of chemical compounds with chemical properties opposite to those of an acid. A base neutralises an acid by taking up the free hydrogen ions in the acid. Mineral bases, such as copper oxide (CuO), are generally stronger than organic bases. A base that is soluble in water is called an alkali. The concentration of a base solution is a major factor determining its alkalinity. Examples of bases include magnesium hydroxide (Mg(OH)₂) which is used in indigestion tablets, and sodium hydroxide (NaOH) which is used in oven cleaners.

Tauira KŌrero

Pēhea nei te kaha o te pāpāhua nei, te konupora waihā (Mg(OH)₂)?

Rārangihia mai ētahi pāpāhua me te whakamahinga o aua pāpāhua.

Whakamahia ai te pāpāhua hei hanga hopi.

WhakamĀrama Āpitihanga

Ka inea te kaha o tētahi pāpāhua i runga i te āwhata pH. Kei runga ake i te 7 ngā pāpāhua katoa, ko te 14 hei tohu i te pāpāhua tino kaha, he ngū te pH7, ko te wai tērā. Ko tā te pāpāhua he huri i te tohu waikawa kia kahurangi te tae. Koia nei ngā tae o te Ranunga Taetohu hei tohu i te pH o tētahi pāpāhua:

Koia nei ētahi pāpāhua e mōhio whānuitia ana:

Pāpāhua	Tōna tohu	Tōna kaha	Hei tauira
konutai waihā	NaOH	he tino kaha	hei mahi hopi
konupūmā waihā	Ca(OH)₂	he kaha	hei whakangū i te waikawa o te oneone
haukini waihā	NH₄OH	he āhua ngoikore	he wē horoi whare
konupora waihā	Mg(OH)₂	he āhua ngoikore	hei whakangū i te waikawa o te puku
konutai winika	CH₃COONa	he ngoikore	hei matū rokiroki kai

Ina whakaranua te waikawa me te pāpāhua, ko te pāhare me te wai ka hua ake. Arā:

waikawa + pāpāhua → pāhare + wai

Pēhea nei te kaha o te pāpāhua nei, te konupora waihā (Mg(OH)₂)?

Rārangihia mai ētahi pāpāhua me te whakamahinga o aua pāpāhua.

Whakamahia ai te pāpāhua hei hanga hopi.