Zitsanzo za mafunso okhudza makhalidwe a mkangano wa mayankho
Makhalidwe a colligative a mayankho ndi makhalidwe omwe amadalira kokha kuchuluka kwa tinthu ta solute mu yankho, osati mtundu kapena mtundu wa solute. Pali mitundu ikuluikulu inayi ya makhalidwe a colligative: kutsika kwa nthunzi, kukwera kwa malo owira, kutsika kwa malo ozizira, ndi kupsinjika kwa osmotic. M'nkhaniyi, tikambirana zitsanzo zingapo za mavuto ndikukambirana za makhalidwe aliwonse a colligative a mayankho.
1. Kuchepa kwa Kupanikizika kwa Nthunzi (Lamulo la Raoult)
Chitsanzo cha mavuto:
Sungunulani magalamu 18 a urea (NH2CONH2) mu magalamu 200 a madzi. Kodi kuchepa kwa kuthamanga kwa nthunzi ya yankho ndi kotani ngati kuthamanga kwa nthunzi ya madzi oyera pa kutentha kwina kuli 23.8 mmHg? (Molar mass ya urea = 60 g/mol)
Kukambirana:
Kuti tiwerengere kutsika kwa kuthamanga kwa nthunzi, tiyenera kuwerengera gawo la mole la solute.
1. Werengani chiwerengero cha ma moles a urea:
\[
\text{Number of moles of urea} = \frac{18 \text{ g}}{60 \text{ g/mol}} = 0.3 \text{ mol}
\]
2. Werengani chiwerengero cha mamolekyu a madzi:
\[
\text{Molar mass of water} = 18 \text{g/mol}
\]
\[
\text{Number of mols of water} = \frac{200 \text{g}}{18 \text{g/mol}} = 11.11 \text{mol}
\]
3. Werengani gawo la mole la solute:
\[
x_{\text{urea}} = \frac{0.3 \text{ mol}}{0.3 \text{ mol} + 11.11 \text{ mol}} = 0.0265
\]
4. Kuchepa kwa mphamvu ya nthunzi:
\[
\Delta P = P_0 \cdot x_{\text{urea}} = 23.8 \text{ mmHg} \times 0.0265 = 0.63 \text{ mmHg}
\]
2. Kukwera kwa Malo Owira
Chitsanzo cha mavuto:
Kodi kuchuluka kwa madzi otentha omwe ali ndi 1 mol NaCl/kg ndi kotani? Kf pa madzi ndi 0.52 °C/m2.
Kukambirana:
NaCl mu yankho imagawanika kukhala ma ioni awiri (Na+ ndi Cl-), kotero van 't Hoff factor (i) ndi 2.
1. Werengani kuchuluka kwa madzi (m):
\[
m = \frac{1 \text{ mol}}{1 \text{ kg}} = 1 \text{ m}
\]
2. Kukwera kwa malo otentha:
\[
\Delta T_b = i \cdot K_b \cdot m = 2 \cdot 0.52 \text{ °C/m} \cdot 1 \text{ m} = 1.04 \text{ °C}
\]
Chifukwa chake, kuchuluka kwa kuwira kwa yankho ndi 1.04 °C.
3. Kutsika kwa Madzi Ozizira
Chitsanzo cha mavuto:
Werengani kuchuluka kwa madzi ozizira omwe ali ndi 0.5 mol ya shuga (C6H12O6)/kg ya madzi. Kf ya madzi ndi 1.86 °C/m2.
Kukambirana:
Shuga sagawanika mu yankho, kotero van 't Hoff factor (i) ndi 1.
1. Werengani kuchuluka kwa madzi (m):
\[
m = \frac{0.5 \text{ mol}}{1 \text{ kg}} = 0.5 \text{ m}
\]
2. Kutsika kwa malo ozizira:
\[
\Delta T_f = i \cdot K_f \cdot m = 1 \cdot 1.86 \text{ °C/m} \cdot 0.5 \text{ m} = 0.93 \text{ °C}
\]
Choncho, kutsika kwa malo ozizira a yankho ndi 0.93 °C.
4. Kupanikizika kwa Osmotic
Chitsanzo cha mavuto:
Werengerani kuthamanga kwa osmotic kwa yankho la urea la 0.1 M pa 27 °C. (R = 0.0821 L·atm/K·mol)
Kukambirana:
Kupanikizika kwa Osmotic (\(\pi\)) kungawerengedwe pogwiritsa ntchito fomula iyi:
\[
\pi = MRT
\]
1. Sinthani kutentha kukhala Kelvin:
\[
T = 27 \malemba{°C} + 273.15 = 300.15 \malemba{K}
\]
2. Werengani kuthamanga kwa osmotic:
\[
\pi = 0.1 \malemba{ M} \nthawi 0.0821 \malemba{ L·atm/K·mol} \nthawi 300.15 \malemba{ K}
\]
\[
\pi = 2.461 \malemba{atm}
\]
Chifukwa chake, kuthamanga kwa osmotic kwa yankho ndi 2.461 atm.
Mapeto
Makhalidwe a colligative a mayankho amapereka chidziwitso chosavuta koma champhamvu cha momwe mayankho amagwirira ntchito kutengera kuchuluka kwa tinthu ta solute. Kudzera mu zitsanzo zomwe zili pamwambapa, titha kumvetsetsa momwe tingawerengere kutsika kwa nthunzi, kukwera kwa boling point, kutsika kwa frozing point, ndi kuthamanga kwa osmotic kwa yankho. Tikukhulupirira kuti mafotokozedwe ndi zitsanzo izi ndizothandiza kumvetsetsa lingaliro la makhalidwe a colligative a mayankho ndi momwe amagwiritsidwira ntchito tsiku ndi tsiku, njira zamafakitale, ndi kafukufuku wasayansi.
