Dokar Boyle, Dokar Charles da Dokar G. Lussac
Dokar Boyle
Robert Boyle ne adam wata (1627–1691) sun gudanar da gwaje-gwaje don bincika alaƙar adadi tsakanin matsin lamba na iskar gas da girma. Wannan gwajin ya ƙunshi sanya wani adadin iskar gas a cikin akwati mai rufewa. A wani kimantawa mai kyau, ya gano cewa idan zafin iskar gas ɗin ya kasance daidai, to yayin da matsin lamba na iskar gas ke ƙaruwa, ƙarfin iskar gas ɗin yana raguwa. Haka nan, lokacin da matsin lamba na iskar gas ya ragu, ƙarfin iskar gas ɗin yana ƙaruwa. Matsin iskar gas yana daidai da girman iskar gas. Wannan dangantaka an san ta da Dokar Boyle. Ta hanyar lissafi:
Ana iya rubuta dokar Boyle kamar haka:
PV = daidaito → daidaito 1
P1 V1 =P2 V2 → lissafi na 2
Ma'anar lissafi na 1 shine cewa a yanayin zafi mai ɗorewa (T), idan matsin lamba (P) na iskar gas ya canza, ƙarar (V) na iskar gas ɗin ma yana canzawa ta yadda samfurin matsin lamba da girma koyaushe yake canzawa. Idan matsin lamba na iskar gas ya ƙaru, ƙarar iskar gas ɗin ta ragu ko akasin haka, idan matsin lamba na iskar gas ya ragu, ƙarar iskar gas ɗin ta ƙaru, don haka samfurin matsin lamba da girma koyaushe yana da ɗorewa.
Jadawalin da ke nuna alaƙar da ke tsakanin girma da matsin lamba yayi kama da wanda ke ƙasa. Dangane da gwaje-gwajen da ya yi, Robert Boyle ya gano cewa yawan iskar gas yana canzawa ba bisa ƙa'ida ba, wanda hakan ke sa layin da ke kan jadawalin ya bayyana a lanƙwasa. Matsin da aka nuna a kan jadawalin shine cikakken matsin lamba, ba matsin lamba na ma'auni ba.
Dokar Charles
Shekaru ɗari bayan Robert Boyle ya gano alaƙar da ke tsakanin girma da matsin lamba, masanin kimiyyar Faransa Jacques Charles (1746–1823) ya binciki alaƙar da ke tsakanin zafin jiki da yawan iskar gas. Dangane da gwaje-gwajensa, ya gano cewa idan matsin lamba na iskar gas ya kasance iri ɗaya, to yayin da zafin iskar gas ke ƙaruwa, yawan iskar ma yana ƙaruwa. Akasin haka, yayin da zafin iskar gas ke raguwa, yawan iskar ma yana raguwa.
Canje-canje a cikin yawan iskar gas saboda canjin zafin jiki yana faruwa akai-akai, don haka layin da ke kan wannan jadawalin yana bayyana a mike. Idan an zana layin da ke kan jadawalin a ƙananan yanayin zafi, zai haɗu da axis a kusan -273°C. oC.
Dangane da gwaje-gwaje da yawa da aka gudanar, an gano cewa kodayake girman canjin girma ga kowane iskar gas ya bambanta, lokacin da aka zana layin da ke kan jadawalin V-T a ƙaramin zafin jiki, layin koyaushe yana yanke axis a kusa da -273 oC. Za mu iya cewa idan aka sanyaya iskar gas zuwa ‐273 oC to girman iskar = 0. Idan aka sake sanyaya iskar har sai zafin ya ƙasa da -273 oC to girman iskar gas ɗin zai zama mara kyau, wani abu da ba zai yiwu ba.
So-273 oC shine mafi ƙarancin zafin jiki da za a iya isa gare shi. Domin layin yana haɗuwa da axis a kusa da ‐273 oC sannan bisa ga yarjejeniyar juna, an tabbatar da cewa mafi ƙarancin zafin jiki da za a iya samu shine -273,15 oC. -273,15 oAna kiran C da cikakken zafin jiki sifili kuma ana amfani da shi azaman nuni ga cikakken sikelin, wanda kuma aka sani da sikelin Kelvin. An sanya wa Kelvin suna ne bayan Lord Kelvin (1824–1907), masanin kimiyyar lissafi na Burtaniya. A wannan sikelin, ana bayyana zafin jiki a cikin Kelvin (K), ba digiri na Kelvin ba (oK). Nisa tsakanin digiri iri ɗaya ne da na sikelin Celsius. 0 K = ‐273,15 oC da 273,15 K = 0 oC.
Za a iya canza zafin jiki a sikelin Celsius zuwa sikelin Kelvin ta hanyar ƙara 273,15, za a iya canza zafin jiki a sikelin Kelvin zuwa sikelin Celsius ta hanyar cire 273,15. A lissafi:
T (K) = T (oC) + 273,15
T (oC) = T (K) - 273,15
Bayani:
T = Zafin jiki
K = Kelvin
C = Celsius
Idan zafin jiki ya bayyana a sikelin Kelvin to jadawalin da ke sama zai yi kama da hoton da ke ƙasa.
Dangane da wannan jadawalin, za a iya kammalawa cewa a matsin lamba mai ɗorewa, yawan iskar gas koyaushe yana daidai da yanayin zafi mai ɗorewa. Idan zafin iskar gas ya ƙaru, girmansa ma yana ƙaruwa; akasin haka, idan zafin iskar gas ya ragu, girmansa ma yana raguwa. Wannan alaƙar ana kiranta da dokar Charles. A lissafi, an rubuta ta kamar haka:
Ƙara ∝ Zafin jiki → Matsi Mai Tsayi
V ∝ T → P mai dorewa
Haka kuma za a iya rubuta dokar Charles kamar haka:
Ma'anar lissafi na 1 shine cewa a matsin lamba mai ɗorewa (P), idan zafin jiki mai ɗorewa (T) na iskar gas ya canza, girman (V) na iskar gas ɗin ma yana canzawa don haka sakamakon kwatantawa tsakanin zafin jiki mai ɗorewa da girma koyaushe yana canzawa. Idan zafin jiki mai ɗorewa na iskar gas ya ƙaru, girman iskar gas ɗin ma yana ƙaruwa, ko akasin haka, idan zafin jiki mai ɗorewa na iskar gas ya ragu, girman iskar gas ɗin ma yana raguwa, don haka kwatancen tsakanin zafin jiki da girma koyaushe yana canzawa. Abin da ake nufi da zafin jiki mai ɗorewa na iskar gas shine zafin iskar gas ɗin da aka bayyana akan sikelin Kelvin. Idan zafin jiki har yanzu yana kan sikelin Celsius, to sai a fara mayar da shi zuwa sikelin Kelvin.
Dokar Gay-Lussac
Joseph Gay-Lussac (1778–1850) ya gudanar da wani gwaji kuma ya gano cewa idan aka ci gaba da daidaita yawan iskar gas, yayin da matsin iskar gas ke ƙaruwa, zafin iskar gas ɗin ma yana ƙaruwa. Akasin haka, yayin da matsin iskar gas ke raguwa, zafin iskar gas ɗin ma yana raguwa. A daidai lokacin da aka daidaita, matsin iskar gas ɗin yana daidai da yanayin zafin iskar gas ɗin. Ana kiran wannan dangantaka da Dokar Gay-Lussac. A lissafi:
Matsi ∝ Zafin jiki → Ƙarar da ba ta canzawa
P ∝ T → V mai dorewa
Ana iya rubuta dokar Gay-Lussac kamar haka:
Ma'anar lissafi na 1 shine cewa a cikin ƙarar da ba ta canzawa ba (V), idan matsin lamba (P) na iskar gas ya canza, zafin jiki na gas ɗin (T) shi ma yana canzawa don haka sakamakon kwatantawa tsakanin matsin lamba da zafin jiki mai kyau ya kasance mai dorewa. A wata ma'anar, idan matsin lamba na iskar gas ya ƙaru, zafin jiki na iskar gas ɗin ma yana ƙaruwa, ko akasin haka, idan matsin lamba na iskar gas ya ragu, zafin jiki na iskar gas ɗin ma yana raguwa, don haka kwatancen tsakanin matsin lamba da zafin jiki koyaushe yana dawwama.
Abin da ake nufi da cikakken zafin iskar gas shine zafin iskar da aka bayyana a ma'aunin Kelvin. Idan zafin yana kan ma'aunin Celsius, to sai a fara mayar da shi zuwa ma'aunin Kelvin.
Yana da mahimmanci a lura cewa dokar Boyle, dokar Charles, da dokar Gay-Lussac suna ba da sakamako mai kyau idan matsin lamba da yawan iskar gas ba su yi yawa ba. Bugu da ƙari, waɗannan dokoki uku suna aiki ne kawai ga iskar gas waɗanda yanayin zafinsu bai kusa da inda zafinsu yake tafasa ba.
Bisa ga wannan gaskiyar, za a iya kammala da cewa dokar Boyle, dokar Charles, da dokar Gay-Lussac ba za a iya amfani da su ga dukkan yanayin iskar gas ba. Domin ba za a iya amfani da su ga dukkan yanayin iskar gas na gaske ba, muna buƙatar ra'ayin iskar gas mai kyau, ko iskar gas mai kyau. Wannan iskar gas mai kyau ba ta wanzu a rayuwar yau da kullun ba. Iskar gas mai kyau kawai tsari ne mai kyau, kama da ra'ayoyin jiki mai tauri da ruwa mai kyau. Saboda haka, muna ɗauka cewa dokokin iskar gas guda uku da ke sama suna aiki a ƙarƙashin duk yanayin iskar gas mai kyau.
Wajen magance matsalolin dokar iskar gas, dole ne a nuna zafin jiki a ma'aunin Kelvin. Idan matsin iskar gas har yanzu matsin lamba ne na aunawa, da farko a mayar da shi zuwa matsin lamba cikakke. Matsi cikakke = matsin lamba na yanayi + matsin lamba na barometricr.
