Mibvunzo yeMienzaniso neKukurukurirana kweKuora Mwoyo kweMagadzirirwo eFreezing Point
Kuora mwoyo kwepfungwa kunokonzerwa nekuomarara kwenzvimbo inotonhora (freezing point depression) chinhu chakakosha mumakemikari ekugadzirisa matambudziko. Zvakakosha nekuti zvinokanganisa maitiro mazhinji ehupenyu, makemikari, uye maindasitiri. Chinyorwa chino chinokurukura mienzaniso yakati wandei yematambudziko ane chekuita nekuora mwoyo kwepfungwa inotonhora uye chinopa hurukuro dzakadzama kuti dzijekese pfungwa iyi.
Kunzwisisa Kuora Mwoyo kweFreezing Point
Kuora kwenzvimbo yekutonhora (freezing point depression) chiitiko apo nzvimbo yekutonhora yechinhu chinonyungudutsa inodzikiswa kana chinhu chinonyungudutsa chikawedzerwa kwachiri. Izvi zvinoitika kana paine dambudziko rehondo, zvichireva kuti kuora kwenzvimbo yekutonhora kunoenderana nehuwandu hwezvinhu zvinonyungudutsa mumhinduro, kwete kuti chinhu chinonyungudutsa chii.
Equation yakajairika inoshandiswa kuverenga kuora mwoyo kwechando ndeiyi:
\[
\Delta T_f = K_f \cdot m
\]
Di mana:
– \(\Delta T_f\) ndiko kuora mwoyo kunokonzera kutonhora.
– \(K_f\) ndicho chinhu chinowanzoonekwa sechinonyungudutsa mvura (freezing point depression constant).
– \(m\) ndiko kusanganiswa kwemvura (mamoles e solute/kg ye solvent).
Muenzaniso weMibvunzo yeKuora Mwoyo kweFreezing Point
Mubvunzo 1
Zvinozivikanwa:
– Mhinduro inogadzirwa nekunyungudutsa magiramu mashanu eNaCl (huremu hwemolar = 58.5 g/mol) mumagiramu mazana maviri emvura.
– Kugadzikana kwenzvimbo yekutonhora (K_f) yemvura i1.86 °C • kg/mol.
Mubvunzo:
Verengai kuti mvura iyi inotonhora zvakadii.
Kukurukurirana:
1. Verenga huwandu hwemvura inobuda muropa (m):
Kutanga, tinoverenga huwandu hwemamoles eNaCl:
\[
\text{mol NaCl} = \frac{\text{huremu hweNaCl (g)}}{\text{huremu hwemolar (g/mol)}} = \frac{5 \text{ g}}{58.5 \text{ g/mol}} = 0.0855 \text{ mol}
\]
Zvadaro, tinoverenga molality (mamoles e solute/kg ye solvent):
\[
\text{molality} = \frac{\text{mol NaCl}}{\text{mass of solvent (kg)}} = \frac{0.0855 \text{ mol}}{0.2 \text{ kg}} = 0.4275 \text{ m}
\]
2. Verengai kuderera kwenzvimbo yechando (\(\Delta T_f\)):
\[
\Delta T_f = K_f \cdot m = 1.86 \text{ °C•kg/mol} \cdot 0.4275 \text{ m} = 0.79545 \text{ °C}
\]
Saka, mushonga uyu uchasangana nekudzikama kwenzvimbo yechando ye0.79545 °C.
Mubvunzo 2
Zvinozivikanwa:
– Mushonga une magiramu gumi eglucose (C₆H₁₂O₆, huremu hwemolar = 180 g/mol) yakanyungudutswa mumagiramu mazana maviri nemakumi mashanu emvura.
– Kudzikama kwemvura panguva yekutonhora kunosvika 1.86 °C •kg/mol.
Mubvunzo:
Chii chinonzi kuderedzwa kwenzvimbo yekutonhora kwemushonga uyu weglucose?
Kukurukurirana:
1. Verenga huwandu hwemvura inobuda muropa (m):
Kutanga, tinoverenga huwandu hwemamoles eglucose:
\[
\text{mol glucose} = \frac{\text{mass of glucose (g)}}{\text{molar weight (g/mol)}} = \frac{10 \text{ g}}{180 \text{ g/mol}} = 0.0556 \text{ mol}
\]
Zvadaro, tinoverenga molality (mamoles e solute/kg ye solvent):
\[
\text{molality} = \frac{\text{mol glucose}}{\text{mass of solvent (kg)}} = \frac{0.0556 \text{ mol}}{0.25 \text{ kg}} = 0.2224 \text{ m}
\]
2. Verengai kuderera kwenzvimbo yechando (\(\Delta T_f\)):
\[
\Delta T_f = K_f \cdot m = 1.86 \text{ °C•kg/mol} \cdot 0.2224 \text{ m} = 0.413664 \text{ °C}
\]
Saka, mhinduro yeglucose ichadzikira ne0.413664 °C.
Mubvunzo 3
Zvinozivikanwa:
– Mushonga unogadzirwa nekunyungudutsa magiramu makumi maviri eurea (NH₂CONH₂, huremu hwemolar = 60 g/mol) mumagiramu mazana mashanu emvura.
– Kugadzikana kwenzvimbo yekutonhora (K_f) yemvura i1.86 °C • kg/mol.
Mubvunzo:
Verengai kuti mvura iyi inotonhora zvakadii.
Kukurukurirana:
1. Verenga huwandu hwemvura inobuda muropa (m):
Kutanga, tinoverenga huwandu hwemamota eurea:
\[
\text{mole urea} = \frac{\text{mass of urea (g)}}{\text{molar weight (g/mol)}} = \frac{20 \text{ g}}{60 \text{ g/mol}} = 0.3333 \text{ mol}
\]
Zvadaro, tinoverenga molality (mamoles e solute/kg ye solvent):
\[
\text{molality} = \frac{\text{mol urea}}{\text{mass of solvent (kg)}} = \frac{0.3333 \text{ mol}}{0.5 \text{ kg}} = 0.6666 \text{ m}
\]
2. Verengai kuderera kwenzvimbo yechando (\(\Delta T_f\)):
\[
\Delta T_f = K_f \cdot m = 1.86 \text{ °C•kg/mol} \cdot 0.6666 \text{ m} = 1.240476 \text{ °C}
\]
Saka, mushonga wacho uchadzikira nekutonhora kwe1.240476°C.
Mubvunzo 4
Zvinozivikanwa:
– Mushonga une magiramu gumi nemashanu eacetic acid (CH₃COOH, huremu hwemolar = 60 g/mol) yakanyungudutswa mumagiramu mazana matatu emvura.
– Kugadzikana kwenzvimbo yekutonhora (K_f) yemvura i1.86 °C • kg/mol.
Mubvunzo:
Chii chinonzi kudonha kwenzvimbo yekutonhora kwemushonga uyu weacetic acid?
Kukurukurirana:
1. Verenga huwandu hwemvura inobuda muropa (m):
Kutanga, tinoverenga huwandu hwemamoles eacetic acid:
\[
\text{mol yeacetic acid} = \frac{\text{mass of acetic acid (g)}}{\text{molar weight (g/mol)}} = \frac{15 \text{ g}}{60 \text{ g/mol}} = 0.25 \text{ mol}
\]
Zvadaro, tinoverenga molality (mamoles e solute/kg ye solvent):
\[
\text{molality} = \frac{\text{mol yeacetic acid}}{\text{mass of solvent (kg)}} = \frac{0.25 \text{ mol}}{0.3 \text{ kg}} = 0.8333 \text{ m}
\]
2. Verengai kuderera kwenzvimbo yechando (\(\Delta T_f\)):
\[
\Delta T_f = K_f \cdot m = 1.86 \text{ °C•kg/mol} \cdot 0.8333 \text{ m} = 1.55 \text{ °C}
\]
Saka, mushonga wacho uchadzikira nekutonhora kwe1.55°C.
Mhedziso
Kuora mwoyo kwenzvimbo yekutonhora chinhu chakakosha mukushandiswa kwakasiyana-siyana kwesainzi uye kwemaindasitiri. Nekunzwisisa maitiro ekuverenga kuora mwoyo kwenzvimbo yekutonhora, tinogona kufanotaura kuti mhinduro dzakasiyana dzichakanganisa sei nzvimbo yekutonhora yemhinduro. Chinyorwa chino chakurukura mienzaniso yakati wandei yematambudziko uye maitiro ekuverenga kuora mwoyo kwenzvimbo yekutonhora kuti uwane mhinduro, zvichikupa hwaro hwakasimba mukunzwisisa pfungwa yekuora mwoyo kwenzvimbo yekutonhora.
