Mafunso ndi Zitsanzo za Kukambirana za Kupsinjika kwa Malo Ozizira kwa Mayankho
Kuvutika maganizo chifukwa cha kuzizira ndi vuto lofunika kwambiri pakupanga mankhwala. Limakhudza njira zambiri zamoyo, mankhwala, ndi mafakitale. Nkhaniyi ikufotokoza zitsanzo zingapo za kuvutika maganizo chifukwa cha kuzizira ndipo ikupereka zokambirana zatsatanetsatane kuti zimveke bwino lingaliro ili.
Kumvetsetsa Kuvutika Maganizo kwa Freezing Point
Kutsika kwa malo ozizira ndi chinthu chomwe chimatsitsa malo ozizira a solvent pamene solute yawonjezeredwa. Izi ndi zochitika za colligative, zomwe zikutanthauza kuti kuchepa kwa malo ozizira kumadalira kuchuluka kwa tinthu ta solute mu yankho, osati kudziwika kwa solute.
Chiyerekezo chachikulu chomwe chimagwiritsidwa ntchito kuwerengera kupsinjika kwa malo ozizira ndi:
\[
\Delta T_f = K_f \cdot m
\]
Kumene:
– \(\Delta T_f\) ndi kufooka kwa malo ozizira.
– \(K_f\) ndiye chizindikiro cha kuzizira kwa malo osungunuka.
– \(m\) ndi kuchuluka kwa yankho (ma mole a solute/kg ya solvent).
Mafunso a Chitsanzo cha Kuvutika Maganizo kwa Malo Ozizira
Funso 1
Ndizodziwika kuti:
– Yankho limapangidwa posungunula magalamu 5 a NaCl (kulemera kwa molar = 58.5 g/mol) mu magalamu 200 a madzi.
– Madzi okhazikika (K_f) ndi 1.86 °C •kg/mol.
Funso:
Werengani kuchuluka kwa madzi ozizira omwe agwiritsidwa ntchito pa yankho ili.
Kukambirana:
1. Werengani kuchuluka kwa madzi (m):
Choyamba, timawerengera kuchuluka kwa ma moles a NaCl:
\[
\text{mol NaCl} = \frac{\text{mass of NaCl (g)}}{\text{molar weight (g/mol)}} = \frac{5 \text{ g}}{58.5 \text{ g/mol}} = 0.0855 \text{ mol}
\]
Kenako, timawerengera molality (ma moles a solute/kg ya 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. Werengani kuchuluka kwa kuzizira kwa malo (\(\Delta T_f\)):
\[
\Delta T_f = K_f \cdot m = 1.86 \text{ °C•kg/mol} \cdot 0.4275 \text{ m} = 0.79545 \text{ °C}
\]
Chifukwa chake, yankho ili lidzakumana ndi kuzizira kwa 0.79545 °C.
Funso 2
Ndizodziwika kuti:
– Yankho lili ndi magalamu 10 a shuga (C₆H₁₂O₆, kulemera kwa molar = 180 g/mol) yosungunuka mu magalamu 250 a madzi.
– Kutsika kwa madzi komwe kumakhazikika pa nthawi yozizira ndi 1.86 °C •kg/mol.
Funso:
Kodi njira iyi ya glucose imakhudza bwanji kuzizira kwa malo osungira shuga?
Kukambirana:
1. Werengani kuchuluka kwa madzi (m):
Choyamba, timawerengera kuchuluka kwa ma moles a glucose:
\[
\text{mol glucose} = \frac{\text{mass of glucose (g)}}{\text{molar weight (g/mol)}} = \frac{10 \text{ g}}{180 \text{ g/mol}} = 0.0556 \text{ mol}
\]
Kenako, timawerengera molality (ma moles a solute/kg ya 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. Werengani kuchuluka kwa kuzizira kwa malo (\(\Delta T_f\)):
\[
\Delta T_f = K_f \cdot m = 1.86 \text{ °C•kg/mol} \cdot 0.2224 \text{ m} = 0.413664 \text{ °C}
\]
Chifukwa chake, yankho la shuga lidzatsika ndi 0.413664 °C.
Funso 3
Ndizodziwika kuti:
– Yankho limapangidwa posungunula magalamu 20 a urea (NH₂CONH₂, kulemera kwa molar = 60 g/mol) mu magalamu 500 a madzi.
– Madzi okhazikika (K_f) ndi 1.86 °C •kg/mol.
Funso:
Werengani kuchuluka kwa madzi ozizira omwe agwiritsidwa ntchito pa yankho ili.
Kukambirana:
1. Werengani kuchuluka kwa madzi (m):
Choyamba, timawerengera kuchuluka kwa urea:
\[
\text{mole urea} = \frac{\text{mass of urea (g)}}{\text{molar weight (g/mol)}} = \frac{20 \text{ g}}{60 \text{ g/mol}} = 0.3333 \text{ mol}
\]
Kenako, timawerengera molality (ma moles a solute/kg ya 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. Werengani kuchuluka kwa kuzizira kwa malo (\(\Delta T_f\)):
\[
\Delta T_f = K_f \cdot m = 1.86 \text{ °C•kg/mol} \cdot 0.6666 \text{ m} = 1.240476 \text{ °C}
\]
Choncho, yankholo lidzakumana ndi kuzizira kwa 1.240476 °C.
Funso 4
Ndizodziwika kuti:
– Yankho lili ndi magalamu 15 a acetic acid (CH₃COOH, kulemera kwa molar = 60 g/mol) yosungunuka mu magalamu 300 a madzi.
– Madzi okhazikika (K_f) ndi 1.86 °C •kg/mol.
Funso:
Kodi yankho la acetic acid limeneli limakhudza bwanji kuzizira kwa malo osungira madzi?
Kukambirana:
1. Werengani kuchuluka kwa madzi (m):
Choyamba, timawerengera kuchuluka kwa ma moles a acetic acid:
\[
\text{mol of acetic acid} = \frac{\text{mass of acetic acid (g)}}{\text{molar weight (g/mol)}} = \frac{15 \text{ g}}{60 \text{ g/mol}} = 0.25 \text{ mol}
\]
Kenako, timawerengera molality (ma moles a solute/kg ya solvent):
\[
\text{molality} = \frac{\text{mol of acetic acid}}{\text{mass of solvent (kg)}} = \frac{0.25 \text{ mol}}{0.3 \text{ kg}} = 0.8333 \text{ m}
\]
2. Werengani kuchuluka kwa kuzizira kwa malo (\(\Delta T_f\)):
\[
\Delta T_f = K_f \cdot m = 1.86 \text{ °C•kg/mol} \cdot 0.8333 \text{ m} = 1.55 \text{ °C}
\]
Choncho, yankholo lidzakumana ndi kuzizira kwa 1.55 °C.
Mapeto
Kuvutika maganizo chifukwa cha kuzizira ndi chinthu chofunikira kwambiri pa ntchito zosiyanasiyana zasayansi ndi mafakitale. Podziwa momwe tingawerengere kuvutika maganizo chifukwa cha kuzizira, titha kuneneratu momwe ma solute osiyanasiyana angakhudzire kuzizira kwa yankho. Nkhaniyi yafotokoza zitsanzo zingapo za mavuto ndi momwe mungawerengere kuvutika maganizo chifukwa cha kuzizira kuti mupeze mayankho, kukupatsani maziko olimba omvetsetsa lingaliro la kuvutika maganizo chifukwa cha kuzizira.
