Molal ndende. Kodi zikutanthauza molar ndi molal ndende?

Molar ndi ndende molal, ngakhale mayina ofanana, makhalidwe a zosiyana. Chachikulu kusiyana ndi kuti tipeze molal ndende mawerengedwe anapangidwa osati buku la njira monga kudziwika molarity, pamene kulemera kwa zosungunulira lapansi.

General zokhudza njira zothanirana ndi solubility

njira woona otchedwa homogeneous dongosolo, womwenso mu kapangidwe kake angapo zigawo, palokha Chrixitu. Mmodzi wa iwo ndi zosungunulira, ndi ena onse zinthu kusungunuka mmenemo. zosungunulira The akuti ndi thunthu mu njira imene ambiri.

Solubility - mankhwala ndi zinthu zina kupanga dongosolo homogeneous - njira imene umakhala wa maatomu munthu, ayoni, mamolekyulu kapena particles. A ndende - muyeso wa solubility.

Choncho, solubility zinthu ndi luso anagawira uniformly mu mawonekedwe a particles pulayimale mu buku la zosungunulira lapansi.

njira oona wachinsinsi motere:

• ndi mtundu wa zosungunulira - sanali amadzimadzi ndi madzi;
• ndi mtundu wa solute - mpweya njira, zidulo, alkalis, salt, etc.
• kuti mogwirizana ndi magetsi - electrolytes (zinthu ndi madutsidwe magetsi) ndipo sanali electrolytes (zinthu osati angathe madutsidwe magetsi);
• ndende - kuchepetsedwa ndi anaikira.

Ndende ndi njira mawu ake

Ndende kuitana zili (kulemera) ndi zinthu kusungunuka wina kuchuluka (kulemera kapena buku) wa zosungunulira, kapena buku kumatanthauza wa njira kwathunthu. Zimachitika mitundu zotsatirazi:

1. ndende chidwi (m'kukoma%) - limatiuza mmene magalamu ambiri solute ali magalamu 100 wa njira.

2. molar ndende - chiwerengero cha timadontho-timadontho galamu pa 1 lita imodzi ya yankho. Izi zikusonyeza angati galamu-tinthu ali okwanira 1 yankho la thunthu.

3. ndende yachibadwa - chiwerengero galamu-zofanana pa 1 lita imodzi ya yankho. Izi zikusonyeza angati zili galamu zofanana wa solute mu 1 lita imodzi ya yankho.

4. molal ndende amasonyeza timadontho-timadontho angati a solute kuchuluka pa 1 kilogalamu wa zosungunulira.

5. Titer Mzimuyo zili (mu magalamu) wa solute kusungunuka 1 milliliter wa njira.

Molar ndi woipa molal osiyana Chrixitu. Taganizirani makhalidwe awo.

Ndende molar

Chilinganizo cha kudziwa kuti:

CV = (v / V), mmene

ndime - chiwerengero cha zinthu kusungunuka mol;

V - okwana buku la njira lita kapena ^M3.

Mwachitsanzo, "0,1 M njira ya H _{2 4"} limasonyeza kuti okwanira 1 njira ngati alipo 0.1 mol (9.8 g) asidi sulfuric .

molal ndende

Nthawi zonse muyenera kuganizira mfundo yakuti molal ndi molar woipa ndi matanthauzo osiyana kotheratu.

ndi molal zimene ambiri njira? Chilinganizo cha kudziŵa ndi:

Masentimita = (v / m), kumene

ndime - chiwerengero cha zinthu kusungunuka mol;

mamita - Unyinji wa zosungunulira ndi, kg.

Mwachitsanzo, kujambula 0,2 M NaOH njira zikutanthauza kuti mu 1 kilogalamu wa madzi (mu nkhani iyi, ndi zosungunulira) Kutha 0.2 mol NaOH.

Njira zina zofunika kuwerengetsera

Ambiri wothandiza mudziwe ukafunidwe kuti ndende molal inaŵerengeredwa. Pakubwezeretsa, zomwe zingakhale zothandiza kwa pothetsa mavuto waukulu ali motere.

Ntchito kuchuluka kwa mankhwala ν kuzindikira nambala inayake ya ma atomu, ma elekitironi, mamolekyulu, ayoni kapena particles ena.

ndime = m / M = N / N A = V / V m, kumene:

• mamita - Unyinji wa pawiri, ga kapena makilogalamu;
• M - molar misa, ga (kapena kg) / mol;
• N - chiwerengero mayunitsi structural;
• N _A - chiwerengero cha mayunitsi structural pa 1 Mfuko la zinthu, Avogadro zonse: ^6,02. October ²³ mol ^{- 1;}
• V - okwana buku la L kapena mamita ^3;
• V _mamita - molar buku malita / Mole kapena ^M3 / mol.

Last masamu motere:

V _mamita = RT / P, kumene

• R - zonse 8,314 J / (mol ^K.);
• T - mpweya kutentha, K;
• P - mpweya kuthamanga Pa.

Zitsanzo za Zolinga za molarity ndi molality. ntchito №1

Kudziwa ndende molar wa hydroxide potaziyamu yothetsera mu buku la 500 ml. Kulemera KOH njira ndi wofanana magalamu 20.

tanthauzo

Molar misa hydroxide potaziyamu ndi:

_KOH M = 39 + 16 + 1 = 56 g / mol.

Timayembekezera zambiri potaziyamu hydroxide ali njira:

ν (KOH) = m / M = 20/56 = 0,36 Mole.

Ife kuganizira kuti buku la njira kuti lofotokozeredwa m'njira malita:

500 ml = 500/1000 = 0.5 malita.

Kudziwa ndende molar wa hydroxide potaziyamu:

CV (KOH) = vesi (KOH) / V (KOH) = 0,36 / 0,5 = 0,72 mol / lita.

ntchito №2

Kodi sulfure okusayidi (IV) m'mikhalidwe yachibadwa (i.e., pamene P = 101325 Pa, ndipo T = 273 K) ayenera kutenga kuti akonze sulfurous asidi njira ndi ndende ya 2.5 mol / lita imodzi ya buku la malita 5?

tanthauzo

Tingamasulire monga asidi sulfurous ali njira:

ν (H _{2 3)} = CV (H _{2 3)} ∙ V (njira) = 2,5 ∙ 5 = 12.5 mol.

Aone kuti pali chiphaso cha asidi sulfurous ali mawonekedwe zotsatirazi:

CHONCHO ₂ + H ₂ O = H _{2 3}

Malinga ndi izi:

ν (CHONCHO ₂₎ = ν (H _{2 3);}

ν (CHONCHO ₂₎ = 12.5 mol.

Kukumbukira kuti m'mikhalidwe yachibadwa 1 Mole mpweya ali ndi buku la malita 22,4, buku patsogolo kwa okusayidi sulfure:

V (CHONCHO ₂₎ = ν (CHONCHO ₂₎ ∙ 22,4 = 12,5 ∙ 22,4 = 280 malita.

ntchito №3

Kudziwa ndende molar wa NaOH mu njira imene ake kulemera nusu, wofanana 25,5%, ndi osalimba wa 1,25 g / ml.

tanthauzo

Anabvomerezedwa ndi njira nyemba mu buku la 1 lita imodzi ndi kudziwa misa:

mamita (njira) = V (njira) ∙ P (njira) = 1000 ∙ 1,25 = 1,250 gram.

Timayembekezera zambiri za nyemba ndi kulemera soda:

mamita (NaOH) = (w ∙ mamita (njira)) / 100% = (25,5 ∙ 1250) / 100 = 319 magalamu.

Molar misa hydroxide ndi sodium wofanana:

M _NaOH = 23 + 16 + 1 = 40 g / mol.

Timayembekezera hydroxide ndi sodium ali chitsanzo:

ndime (NaOH) = m / M = 319/40 = 8 mol.

Kudziwa ndende molar ya soda ndi:

CV (NaOH) = m / V = 8/1 = 8 mol / lita.

ntchito №4

Mu madzi (100 magalamu) anali kusungunuka mchere wolemera magalamu 10. NaCl. Ikani ndende ya njira (molality).

tanthauzo

Unyinji molar wa NaCl ndi wofanana ndi:

M _NaCl = 23 + 35 = 58 g / mol.

Number NaCl zopezeka njira:

ν (NaCl) = m / M = 10/58 = 0,17 Mole.

Mu nkhani iyi, zosungunulira ndi madzi:

magalamu 100 a madzi = 100/1000 = 0.1 makilogalamu H ₂ Inu mu njira.

Molal ndende ya njira adzakhala wofanana:

Cm (NaCl) = vesi (NaCl) / mamita (madzi) = 0.17 / 0.1 = 1.7 mol / kg.

ntchito №5

Kudziwa ndende molal kwa 15% NaOH soda njira.

tanthauzo

15% soda njira zikutanthauza kuti aliyense magalamu 100 njira lili magalamu 15 NaOH ndi 85 magalamu madzi. Kapena kuti aliyense makilogalamu 100 Njira makilogalamu 15 NaOH ndi 85 makilogalamu madzi. Kuti akonze izo, m'pofunika mu magalamu 85 (makilogalamu) H ₂ O kusungunuka 15 gm (kg) ya soda.

Molar misa ndi sodium wochuluka hydroxide:

M _NaOH = 23 + 16 + 1 = 40 g / mol.

Tsopano ife tikupeza kuchuluka kwa hydroxide ndi sodium mu njira:

ν = m / M = 15/40 = 0.375 mol.

zosungunulira kulemera (madzi) mu makilogalamu:

magalamu 85 H ₂ O = 85/1000 = 0.085 makilogalamu H ₂ Inu mu njira.

Kenako anatsimikiza molal ndende:

Masentimita = (ν / mamita) = 0.375 / 0.085 = 4,41 mol / kg.

Malinga ndi vuto izi lililonse angathe kuthetsedwa ndi ambiri ena kudziwa molality ndi molarity.