Laʻana o kahi nīnau kūkākūkā ma ke kaomi Osmotic o nā hopena
Pendahuluan
He mea nui ke kaomi osmotic i ka kemika a me ka biology. ʻO ia ke kaomi e pono ai e pale i ke kahe ʻana o ka wai ma waena o kahi membrane semipermeable mai kahi hopena o ka haʻahaʻa haʻahaʻa i kahi hopena o ka nui kiʻekiʻe. He mea nui ka hoʻomaopopo ʻana i ke kaomi osmotic i nā ʻano hana like ʻole, e like me nā kaʻina hana olaola i loko o nā cell, ka mālama ʻana i ka wai, a me ka hoʻolālā lāʻau lapaʻau. No ka hoʻākāka pono ʻana i kēia manaʻo, e kūkākūkā mākou i kekahi mau pilikia hoʻohālike a me nā hoʻonā e pili ana i ke kaomi osmotic o nā hoʻonā.
Nīnau 1: Ke helu ʻana i ke kaomi Osmotic o ka hopena kō
Nīnau:
Ua hoʻoheheʻe ʻia ʻelua grama o ka sucrose (C12H22O11) i loko o ka wai e hana i ka nui o 500 mL. He aha ke kaomi osmotic o kēia hopena ma 25°C? (E hoʻohana iā R = 0.0821 L·atm·K^-1·mol^-1 a me ka nui molar o ka sucrose = 342 g/mol).
Kūkākūkā:
1. E helu i ka molarity o ka hopena:
Molarity (M) = \( \dfrac{\text{Helu o nā moles o ka solute}}{\text{Ka nui o ka hopena ma nā lita}} \)
Helu o nā mole o ka sucrose = \( \dfrac{2 \text{ g}}{342 \text{ g/mol}} \) = 0.00585 mol
Ka nui o ka hopena = 500 mL = 0.5 L
Molarity (M) = \( \dfrac{0.00585 \text{ mol}}{0.5 \text{ L}} \) = 0.0117 M
2. Ke helu ʻana i ke kaomi osmotic:
Kaomi osmotic (π) = MRT
Ma hea:
M = 0.0117 mol/L
R = 0.0821 L atm K^-1 mol^-1
T = 25°C = 298 K (no ka mea, pono ke ana wela ma Kelvin)
π = (0.0117 mol/L)(0.0821 L·atm·K^-1·mol^-1)(298 K)
π = 0.286 atm
No laila, ʻo ke kaomi osmotic o ka hopena sucrose he 0.286 atm.
Nīnau 2: Kaomi Osmotic o ka Electrolyte Solution
Nīnau:
He aha ke kaomi osmotic o kahi hopena NaCl me ka nui o 0.2 M ma ka mahana o 27°C? (Ua ʻike ʻia ʻo NaCl kahi electrolyte e hoʻokaʻawale loa i loko o Na+ a me Cl- me R = 0.0821 L·atm·K^-1·mol^-1)
Kūkākūkā:
1. E helu i ke kekelē o ka dissociation:
NaCl → Na+ + Cl-
Ma muli o ka hoʻokaʻawale loa ʻia ʻana o NaCl, ʻo ka huina o nā ʻāpana i loko o ka hopena he pālua ia o nā mole o NaCl.
Ka huina o nā ʻāpana = 2 × ka helu o nā mole o NaCl
2. Ke helu ʻana i ke kaomi osmotic:
Kaomi osmotic (π) = iMRT
Ma hea:
ʻo i = 2 (no ka mea, aia he 2 ʻano o nā ion, ʻo Na+ a me Cl-)
M = 0.2 mol/L
R = 0.0821 L atm K^-1 mol^-1
T = 27°C = 300 K
π = (2)(0.2 mol/L)(0.0821 L·atm·K^-1·mol^-1)(300 K)
π = 9.852 atm
No laila, ʻo ke kaomi osmotic o kahi hopena 0.2 M NaCl ma 27°C he 9.852 atm.
Nīnau 3: Kaomi Osmotic i loko o nā Glucose a me nā Fructose Solutions
Nīnau:
Hana ʻia kahi hopena ma ka hoʻoheheʻe ʻana i 1 mole o ka glucose (C6H12O6) a me 1 mole o ka fructose (C6H12O6) i loko o 1 lita o ka wai. He aha ke kaomi osmotic o ka hopena ma 37°C? (E hoʻohana iā R = 0.0821 L atm K^-1 mol^-1)
Kūkākūkā:
1. E helu i ka huina o nā mole:
Ka huina o nā mole = 1 mole o ka glucose + 1 mole o ka fructose = 2 mole
2. Ke helu ʻana i ke kaomi osmotic:
Kaomi osmotic (π) = MRT
Ma hea:
M = 2 mol/L (no ka mea, aia he 2 moles i loko o 1 lita o ka wai)
R = 0.0821 L atm K^-1 mol^-1
T = 37°C = 310 K
π = (2 mol/L)(0.0821 L·atm·K^-1·mol^-1)(310 K)
π = 50.942 atm
No laila, ʻo ke kaomi osmotic o kahi hopena e loaʻa ana he 1 mole o ka glucose a me 1 mole o ka fructose i loko o 1 lita o ka wai ma 37°C he 50.942 atm.
Nīnau 4: Ka Hui ʻana o ʻElua Mea ʻAʻole Electrolyte
Nīnau:
He aha ke kaomi osmotic o kahi hui ʻana i loaʻa i ka 0.5 mol o ka urea (CO(NH2)2) a me 0.5 mol o ka ethanol (C2H5OH) i loko o 1 lita o ka wai ma 20°C? (R = 0.0821 L·atm·K^-1·mol^-1)
Kūkākūkā:
1. E helu i ka huina o nā mole i loko o ka hopena:
Ka huina o nā mole = 0.5 mol urea + 0.5 mol ethanol = 1 mol
2. Ke helu ʻana i ke kaomi osmotic:
Kaomi osmotic (π) = MRT
Ma hea:
M = 1 mol/L (no ka mea, aia he 1 moles i loko o 1 lita o ka wai)
R = 0.0821 L atm K^-1 mol^-1
T = 20°C = 293 K
π = (1 mol/L)(0.0821 L·atm·K^-1·mol^-1)(293 K)
π = 24.0633 atm
No laila, ʻo ke kaomi osmotic o kahi hui ʻana e loaʻa ana he 0.5 mol o ka urea a me 0.5 mol o ka ethanol i loko o 1 lita o ka wai ma 20°C he 24.0633 atm.
Ka hopena
Mai ka pilikia hoʻohālike ma luna, hiki iā mākou ke hoʻomaopopo pehea e helu ai i ke kaomi osmotic ma lalo o nā kūlana like ʻole. Hoʻopilikia ʻia ke kaomi osmotic e nā mea e like me ka nui o ka hopena, ke ʻano solute (electrolyte a i ʻole non-electrolyte), a me ka mahana. Hilinaʻi ka loiloi makemakika ma hope o ke kaomi osmotic i nā loina kumu i kuhikuhi ʻia e ke kānāwai kinoea kūpono. Me ka hoʻomaopopo maikaʻi ʻana i kēia manaʻo, hiki iā mākou ke hoʻopili iā ia i nā kūlana hana like ʻole i ka kemika a me ka biology.
