Eritmalarning bug 'bosimini pasaytirish bo'yicha namunaviy savollar va muhokama
Eritmaning bugʻ bosimining pasayishi (bugʻ bosimining pasayishi) eritmalarning kolligativ xususiyati boʻlib, u faqat erigan zarrachalar soniga bogʻliq boʻlib, bu zarrachalarning kimyoviy tabiatiga bogʻliq emas. Tushunishni osonlashtirish uchun biz bu tushunchani bir nechta misollar va batafsil muhokamalar orqali muhokama qilamiz.
Bug 'bosimining pasayishining asosiy tushunchasi
Uchuvchan modda erituvchida eriganida, eritmaning bug 'bosimi odatda bir xil haroratda sof erituvchining bug 'bosimidan pastroq bo'ladi. Bu hodisa bug 'bosimini pasaytirish deb nomlanadi. Bu jarayonning asosiy sababi erituvchi molekulalarining gaz fazasiga o'tish ehtimolini kamaytiradigan va shu bilan bug 'bosimini pasaytiradigan erigan zarrachalarning mavjudligidir.
Bug 'bosimining pasayishini quyidagi formula yordamida hisoblash mumkin:
\[ \Delta P = P^\text{0} – P \]
Qayerda:
– \( \Delta P \) bug 'bosimining pasayishidir.
– \( P^\text{0} \) sof erituvchining bug 'bosimi.
– \( P \) eritmaning bug 'bosimi.
Bug 'bosimining pasayishini Raoult tenglamasi yordamida ham quyidagicha ifodalash mumkin:
\[ \Delta P = x_{\text{eritma}} \cdot P^\text{0} \]
Qayerda:
– \( x_{\text{erigan modda}} \) erigan moddaning mol ulushidir.
Quyidagi misollar uchun, standart sharoitlarda bizda sof erituvchi va turli xil erigan moddalar bor deb faraz qilaylik.
1-namuna savol
Savol:
Aytaylik, bizda 90 gramm suvda erigan 10 gramm karbamid (NH2CONH2) dan iborat eritma bor. Muayyan haroratda toza suvning bug 'bosimi 23.76 mm sim. ust. ga teng. Eritmaning bug 'bosimini hisoblang.
Munozara:
1-qadam: Karbamid va suvning mol miqdorini hisoblang.
– Karbamidning molyar massasi (NH₂(_2₂)CONH₂(_2₂)): 60 g/mol.
– Karbamid mollari soni:
\[ \text{mol karbamid} = \frac{10\text{ g}}{60\text{ g/mol}} = 0.167 \text{mol} \]
– Suvning molyar massasi (H\(_2\)O): 18 g/mol.
– Suv mollari soni:
\[ \text{suv mollari} = \frac{90\text{ g}}{18\text{ g/mol}} = 5 \text{ mol} \]
2-qadam: Karbamidning mol ulushini hisoblang.
\[ x_{\text{karbamid}} = \frac{\text{mole karbamid}}{\text{mole karbamid} + \text{mole water}} = \frac{0.167}{0.167 + 5} = 0.0326 \]
3-qadam: Bug 'bosimining pasayishini hisoblang.
\[ \Delta P = x_{\text{urea}} \cdot P^\text{0}_{\text{air}} \]
\[ \Delta P = 0.0326 \cdot 23.76 \text{ mmHg} = 0.774 \text{ mmHg} \]
4-qadam: Eritmaning bug 'bosimini hisoblang.
\[ P_{\text{yechim}} = P^\text{0}_{\text{water}} – \Delta P \]
\[ P_{\matn{yechim}} = 23.76 \matn{ mmHg} – 0.774 \matn{ mmHg} = 22.986 \matn{ mmHg} \]
2-namuna savol
Savol:
Eritma 58.5 g natriy xlorid (NaCl) ni 200 g suvda eritib tayyorlanadi. Toza suvning bug 'bosimi 92.5 mm sim. ust. bo'lgan 50°C da bug' bosimining pasayishini hisoblang.
Munozara:
1-qadam: NaCl va suvning mol sonini hisoblang.
– NaCl ning molyar massasi: 58.5 g/mol.
– NaCl mollari soni:
\[ \text{mol NaCl} = \frac{58.5\text{ g}}{58.5\text{ g/mol}} = 1 \text{mol} \]
– Suvning molyar massasi (H\(_2\)O): 18 g/mol.
– Suv mollari soni:
\[ \text{suv mollari} = \frac{200\text{ g}}{18\text{ g/mol}} = 11.11 \text{ mol} \]
2-qadam: NaCl ning to'liq ionlanishi har bir formula birligida 2 ta ion hosil qilishini yodda tuting (Na\(^+\) va Cl\(^-\)).
\[ n_{\text{jami}} = n_{\text{NaCl}} \cdot 2 = 1 \cdot 2 = 2 \text{ mol ionlari} \]
3-qadam: Erigan moddaning mol ulushini hisoblang.
\[ x_{\text{NaCl}} = \frac{n_{\text{jami}}}{n_{\text{jami}} + n_{\text{air}}} = \frac{2}{2 + 11.11} = 0.152 \]
4-qadam: Bug 'bosimining pasayishini hisoblang.
\[ \Delta P = x_{\text{NaCl}} \cdot P^\text{0}_{\text{air}} \]
\[ \Delta P = 0.152 \cdot 92.5 \text{ mmHg} = 14.06 \text{ mmHg} \]
3-namuna savol
Savol:
Agar 20 gramm glyukoza (C\(_6\)H\(_{12}\)O\(_6\)) 150 gramm suvda erigan bo'lsa va 25°C da toza suvning bug' bosimi 23.8 mm sim. ust. bo'lsa, eritmaning bug' bosimini hisoblang.
Munozara:
1-qadam: Glyukoza va suvning mol miqdorini hisoblang.
– Glyukozaning molyar massasi: 180 g/mol.
– Glyukoza mollari soni:
\[ \text{mol glyukoza} = \frac{20\text{ g}}{180\text{ g/mol}} = 0.111 \text{mol} \]
– Suvning molyar massasi (H\(_2\)O): 18 g/mol.
– Suv mollari soni:
\[ \text{suv mollari} = \frac{150\text{ g}}{18\text{ g/mol}} = 8.33 \text{ mol} \]
2-qadam: Glyukozaning mol fraksiyasini hisoblang.
\[ x_{\text{glyukoza}} = \frac{\text{mol glyukoza}}{\text{mol glyukoza} + \text{mol suv}} = \frac{0.111}{0.111 + 8.33} = 0.0132 \]
3-qadam: Bug 'bosimining pasayishini hisoblang.
\[ \Delta P = x_{\text{glyukoza}} \cdot P^\text{0}_{\text{water}} \]
\[ \Delta P = 0.0132 \cdot 23.8 \text{ mmHg} = 0.314 \text{ mmHg} \]
4-qadam: Eritmaning bug 'bosimini hisoblang.
\[ P_{\text{yechim}} = P^\text{0}_{\text{water}} – \Delta P \]
\[ P_{\matn{yechim}} = 23.8 \matn{ mmHg} – 0.314 \matn{ mmHg} = 23.486 \matn{ mmHg} \]
Yopish
Yuqoridagi misollardan ko'rinib turibdiki, agar biz erigan modda va erituvchining mol sonini, shuningdek, sof erituvchining bug 'bosimini bilsak, eritmaning bug' bosimining pasayishini osongina hisoblash mumkin. Ushbu kontseptsiya ko'plab muhim qo'llanmalarga ega, ayniqsa, eritma xususiyatlarini boshqarish juda muhim bo'lgan kimyo va farmatsevtika sanoatida. Ushbu kontseptsiyani yaxshi tushunish eritmalarning termodinamik xususiyatlarini keyingi o'rganishga ham yordam beradi.
