Mibvunzo yeMienzaniso & Kukurukurirana nezveKuderedza Kumanikidzwa kweUtsi hweMhepo
Kuderera kwekumanikidzwa kwemhepo yemushonga (Vapor Pressure Depression) ipfungwa yemushonga inongoenderana nehuwandu hwezvinhu zvakanyungudutswa kwete hunhu hwemakemikari ezvinhu izvozvo. Kuti tinzwisise zviri nyore, tichakurukura pfungwa iyi kuburikidza nemienzaniso yakati wandei nekukurukurirana kwakadzama.
Pfungwa Yekutanga Yekudonha Kwemhepo Inopisa
Kana chinhu chinoputika chikanyungudutswa mumusanganiswa wezvinhu kuti chigadzire mhinduro, kumanikidzwa kwemhepo yemusanganiswa wezvinhu kunowanzova kwakaderera pane kumanikidzwa kwemhepo yemusanganiswa wezvinhu zvakachena pakupisa kwakafanana. Chiitiko ichi chinozivikanwa sekuderedzwa kwemhepo. Chikonzero chikuru cheizvi ndechekuvapo kwezvikamu zvinonyungudutswa, izvo zvinoderedza mukana wekuti mamorekuru emvura apinde muchikamu chegasi, nokudaro zvichideredza kumanikidzwa kwemhepo.
Kuderera uku kwekumanikidzwa kwemhepo kunogona kuverengerwa uchishandisa fomura:
\[ \Delta P = P^\mashoko{0} – P \]
Di mana:
– \( \Delta P \) kudzikira kwekumanikidzwa kwemhepo.
– \( P^\text{0} \) ndiko kumanikidzwa kwemhepo inonyungudutsa yakachena.
– \( P \) ndiko kumanikidzwa kweutsi hwemushonga.
Kudonha kwekumanikidzwa kwemhepo kunogonawo kuratidzwa uchishandisa equation yaRaoult seizvi:
\[ \Delta P = x_{\text{solute}} \cdot P^\text{0} \]
Di mana:
– \( x_{\text{solute}} \) ndicho chikamu chemole che solute.
Pamienzaniso inotevera, ngatitii tine solvent yakachena uye solutes dzakasiyana-siyana pasi pemamiriro akajairwa.
Muenzaniso Mubvunzo 1
Mubvunzo:
Ngatitii tine mhinduro ine magiramu gumi eurea (NH2CONH2) yakanyungudutswa mumagiramu makumi mapfumbamwe emvura. Kumanikidzwa kwemvura yakachena patembiricha yakati ndeye 23.76 mmHg. Verenga kumanikidzwa kwemvura yakachena.
Kukurukurirana:
Danho 1: Verenga huwandu hwemamoles eurea nemvura.
– Molar huremu hweurea (NH\(_2\)CONH\(_2\)): 60 g/mol.
– Huwandu hwemamota eurea:
\[ \text{mol urea} = \frac{10\text{ g}}{60\text{ g/mol}} = 0.167 \text{ mol} \]
– Huremu hwemvura (H\(_2\)O): 18 g/mol.
– Huwandu hwemamota emvura:
\[ \text{moles of water} = \frac{90\text{ g}}{18\text{ g/mol}} = 5 \text{ mol} \]
Danho rechipiri: Verenga chikamu chemole cheurea.
\[ x_{\text{urea}} = \frac{\text{mole urea}}{\text{mole urea} + \text{mole water}} = \frac{0.167}{0.167 + 5} = 0.0326 \]
Danho rechitatu: Verenga kuderera kwekumanikidzwa kwemhepo.
\[ \Delta P = x_{\text{urea}} \cdot P^\text{0}_{\text{air}} \]
\[ \Delta P = 0.0326 \cdot 23.76 \text{ mmHg} = 0.774 \text{ mmHg} \]
Danho rechina: Verenga kumanikidzwa kwemvura mumushonga.
\[ P_{\text{solution}} = P^\text{0}_{\text{water}} – \Delta P \]
\[ P_{\text{solution}} = 23.76 \text{ mmHg} – 0.774 \text{ mmHg} = 22.986 \text{ mmHg} \]
Muenzaniso Mubvunzo 2
Mubvunzo:
Mhinduro inogadzirwa nekunyungudutsa 58.5 g ye sodium chloride (NaCl) mu 200 g yemvura. Verenga kudzika kwesimba remhepo pa50°C apo simba remhepo remvura yakachena riri 92.5 mmHg.
Kukurukurirana:
Danho 1: Verenga huwandu hwemamoles eNaCl nemvura.
– Huremu hweNaCl: 58.5 g/mol.
- Huwandu hwemamota eNaCl:
\[ \text{mol NaCl} = \frac{58.5\text{ g}}{58.5\text{ g/mol}} = 1 \text{ mol} \]
– Huremu hwemvura (H\(_2\)O): 18 g/mol.
– Huwandu hwemamota emvura:
\[ \text{moles of water} = \frac{200\text{ g}}{18\text{ g/mol}} = 11.11 \text{ mol} \]
Danho rechipiri: Yeuka kuti ionization yakakwana yeNaCl inogadzira maion maviri payuniti imwe neimwe yefomula (Na\(^+\) uye Cl\(^-\)).
\[ n_{\text{total}} = n_{\text{NaCl}} \cdot 2 = 1 \cdot 2 = 2 \text{mol ions} \]
Danho rechitatu: Verenga chikamu chemole che solute.
\[ x_{\text{NaCl}} = \frac{n_{\text{total}}}{n_{\text{total}} + n_{\text{air}}} = \frac{2}{2 + 11.11} = 0.152 \]
Danho rechitatu: Verenga kuderera kwekumanikidzwa kwemhepo.
\[ \Delta P = x_{\text{NaCl}} \cdot P^\text{0}_{\text{air}} \]
\[ \Delta P = 0.152 \cdot 92.5 \text{ mmHg} = 14.06 \text{ mmHg} \]
Muenzaniso Mubvunzo 3
Mubvunzo:
Kana magiramu makumi maviri eglucose (C\(_6\)H\(_{12}\)O\(_6\)) akanyungudutswa mumagiramu zana nemakumi mashanu emvura, uye kumanikidzwa kwemvura yakachena pa25°C kuri 23.8 mmHg, verenga kumanikidzwa kwemvura yakachena yemushonga.
Kukurukurirana:
Danho 1: Verenga huwandu hwemamoles eglucose nemvura.
– Glucose ine molar huremu: 180 g/mol.
– Huwandu hwemamota eglucose:
\[ \text{mol glucose} = \frac{20\text{ g}}{180\text{ g/mol}} = 0.111 \text{ mol} \]
– Huremu hwemvura (H\(_2\)O): 18 g/mol.
– Huwandu hwemamota emvura:
\[ \text{moles of water} = \frac{150\text{ g}}{18\text{ g/mol}} = 8.33 \text{ mol} \]
Danho rechipiri: Verenga chikamu chemole cheglucose.
\[ x_{\text{glucose}} = \frac{\text{mol glucose}}{\text{mol glucose} + \text{mole water}} = \frac{0.111}{0.111 + 8.33} = 0.0132 \]
Danho rechitatu: Verenga kuderera kwekumanikidzwa kwemhepo.
\[ \Delta P = x_{\text{glucose}} \cdot P^\text{0}_{\text{water}} \]
\[ \Delta P = 0.0132 \cdot 23.8 \text{ mmHg} = 0.314 \text{ mmHg} \]
Danho rechina: Verenga kumanikidzwa kwemvura mumushonga.
\[ P_{\text{solution}} = P^\text{0}_{\text{water}} – \Delta P \]
\[ P_{\text{solution}} = 23.8 \text{ mmHg} – 0.314 \text{ mmHg} = 23.486 \text{ mmHg} \]
Penutup
Kubva mumienzaniso iri pamusoro, tinogona kuona kuti kudzikiswa kwesimba remhepo (vapor pressure) yemushonga kunogona kuverengerwa zviri nyore kana tikaziva huwandu hwemamoles emushonga unonyungudutsa (solute) nemushonga unonyungudutsa (solvent), pamwe nekumanikidzwa kwesimba remhepo (vapor pressure) yemushonga unonyungudutsa (pure solvent). Pfungwa iyi ine mashandisirwo akawanda akakosha, kunyanya mumaindasitiri emakemikari nemishonga, uko kudzora hunhu hwemushonga kwakakosha. Kunzwisisa kwakanaka kwepfungwa iyi kunobatsirawo mukudzidza zvimwe nezvehunhu hwemushonga unonyungudutsa (thermodynamic properties).
