Isibonelo Semibuzo Yengxoxo Ye-Calorimetry
Ku-physics, i-calorimetry iyigatsha lesayensi elifunda ukulinganiswa kokushisa ekuphenduleni kwamakhemikhali noma izinguquko zomzimba. Ithuluzi elisetshenziselwa ukulinganisa inani lokushisa libizwa ngokuthi i-calorimeter. I-calorimetry idlala indima ebalulekile, ikakhulukazi ku-thermodynamics kanye ne-physical chemistry, lapho izinguquko emandleni okushisa zibonwa futhi zilinganiswa khona.
Izimiso Eziyisisekelo Ze-Calorimetry
Isimiso esiyisisekelo se-calorimetry sisekelwe emthethweni wokulondolozwa kwamandla, okungukuthi amandla awakwazi ukudalwa noma ukubhujiswa, kodwa angaguqulwa kuphela kusuka kolunye uhlobo lwamandla aye kolunye. Ngokwesimo se-calorimetry, amandla okushisa alahleka uhlelo kumele alingane namandla okushisa amuncwa yimvelo. Ithuluzi eliyinhloko ekuhlolweni kwe-calorimetry ngokuvamile i-calorimeter, engaba i-calorimeter elula, okungukuthi i-calorimeter yamanzi, noma i-calorimeter eyinkimbinkimbi kakhulu, njenge-calorimeter yebhomu.
Amafomula Ayisisekelo E-Calorimetry
Ifomula eyisisekelo ku-calorimetry yile:
\[ Q = m \cdot c \cdot \Delta T \]
Kuphi:
– \( Q \) inani lokushisa (kuma-joules noma ama-calories)
– \( m \) isisindo sale nto (ngamagremu noma amakhilogramu)
– \( c \) ukushisa okuthile kwale nto (ku-J/(g°C) noma ku-cal/(g°C))
– \( \Delta T \) ushintsho lokushisa (ngo-°C)
Ake sibheke eminye imibuzo eyisibonelo kanye nezingxoxo ukuze siqonde kangcono umqondo kanye nokusetshenziswa kwe-calorimetry.
Imibuzo Eyisibonelo kanye Nengxoxo 1
Umbuzo:
Ingcezu yensimbi engamagremu angu-200 ishiswa ibe ngu-100°C bese ifakwa emanzini angamagremu ayi-100 ku-20°C. Izinga lokushisa lokugcina lengxube lingu-27°C. Thola ukushisa okuqondile kwensimbi! (ukushisa okuqondile kwamanzi = 4,18 J/(g°C))
Ingxoxo:
Isinyathelo sokuqala ukubala ukushisa okumuncwa ngamanzi. Sebenzisa ifomula eyisisekelo:
\[ Q_{\text{air}} = m_{\text{air}} \cdot c_{\text{air}} \cdot \Delta T_{\text{air}} \]
Nge-\( m_{\text{air}} = 100 \) amagremu, \( c_{\text{air}} = 4.18 \) J/(g°C), kanye ne-\( \Delta T_{\text{air}} = 27°C – 20°C = 7°C \),
\[ Q_{\text{air}} = 100 \times 4.18 \times 7 = 2926 \text{J} \]
Ukushisa okukhishwa yinsimbi kufana nokushisa okumuncwa ngamanzi, ngakho-ke:
\[ Q_{\text{metal}} = 2926 \text{ J} \]
Ukusebenzisa ifomula yokushisa:
\[ m_{\text{metal}} \cdot c_{\text{metal}} \cdot \Delta T_{\text{metal}} = Q_{\text{metal}} \]
nge \( m_{\text{metal}} = 200 \) amagremu, \(\Delta T_{\text{metal}} = 100°C – 27°C = 73°C \),
\[ 200 \cdot c_{\text{metal}} \cdot 73 = 2926 \text{ J} \]
\[ c_{\text{metal}} = \frac{2926}{200 \times 73} \]
\[ c_{\text{metal}} = 0.2 \text{ J/(g°C)} \]
Ngakho-ke, ukushisa okukhethekile kwensimbi kungu-0.2 J/(g°C).
Imibuzo Eyisibonelo kanye Nengxoxo 2
Umbuzo:
Ibhulokhi yeqhwa enobunzima obungu-50 g ekushiseni okungu-0°C ifakwa ku-200 g wamanzi ekushiseni okungu-30°C ku-calorimeter. Thola izinga lokushisa lokugcina lengxube ngemuva kokufinyelela ukulingana kokushisa! (ukushisa kokuhlanganiswa kweqhwa = 334 J/g, ukushisa okuqondile kwamanzi = 4,18 J/g°C)
Ingxoxo:
Isinyathelo sokuqala ukubala ukushisa okudingekayo ukuze kuncibilikiswe iqhwa:
\[ Q_{\text{melt}} = m_{\text{es}} \cdot L \]
ngamagremu angu-\( m_{\text{es}} = 50 \) kanye no-\( L = 334 \) J/g,
\[ Q_{\text{melting}} = 50 \izikhathi 334 = 16700 \text{ J} \]
Okulandelayo, thola ukushisa okumuncwa yiqhwa ngemva kokuncibilika ukuze kufinyelelwe izinga lokushisa lokugcina \( T \) (uma ucabanga ukuthi u-T izinga lokushisa lokugcina lenhlanganisela):
\[ Q_{\text{ice water}} = m_{\text{es}} \cdot c_{\text{air}} \cdot (T – 0°C) \]
nge \( c_{\text{air}} = 4.18 \text{ J/g°C} \),
\[ Q_{\text{water ice}} = 50 \times 4.18 \times T \]
Ukushisa okukhishwa ngamanzi abandayo (kusukela ku-30°C kuya ku-T):
\[ Q_{\text{air}} = m_{\text{air}} \cdot c_{\text{air}} \cdot (30°C – T) \]
ngamagremu angu- \( m_{\text{air}} = 200 \) ,
\[ Q_{\text{air}} = 200 \izikhathi 4.18 \izikhathi (30 – T) \]
Ekulinganisweni kokushisa, inani lokushisa elimuncwa yiqhwa (ukuze lincibilike bese lishiswa ku-T) lizolingana nenani lokushisa okukhishwe ngamanzi:
\[ Q_{\text{melt}} + Q_{\text{amanzi eqhwa}} = Q_{\text{amanzi}} \]
\[ 16700 + 50 \izikhathi 4.18 \izikhathi T = 200 \izikhathi 4.18 \izikhathi (30 - T) \]
\[ 16700 + 209T = 8360 \izikhathi (30 – T) \]
\[ 16700 + 209T = 250800 – 8360T \]
\[ 8569T = 234100 \]
\[ T = \frac{234100}{8569} \cishe kube ngu-27.3°C \]
Ngakho-ke, izinga lokushisa lokugcina lenhlanganisela ngemva kokufinyelela ukulingana kokushisa lingaba ngu-27.3°C.
Isiphetho
I-Calorimetry iyindlela ebalulekile ku-physics nakumakhemikhali esetshenziselwa ukunquma inani lamandla okushisa enkambisweni yomzimba noma yamakhemikhali. Sisebenzisa izimiso eziyisisekelo kanye namafomula e-calorimetry, singabala amapharamitha ahlukahlukene njengokushisa okuthile kwento, ushintsho lokushisa, noma amandla adonswa/akhishwa enkambisweni. Kulesi sihloko, sibheke izinkinga eziyisibonelo kanye nezixazululo zazo kumongo wokuqonda i-calorimetry. Ukuqonda kahle le mibono kubalulekile ekuxazululeni izinkinga ezahlukahlukene ze-thermodynamic kanye nezinye izinhlelo zokusebenza ezisebenzayo.
