Molal taro. Me ake nufi da matauni da molal maida hankali?

Matauni da molal taro, duk da irin wannan sunaye, da dabi'u ne daban-daban. Babban bambancin shi ne cewa a kayyade molal taro lissafi ne sanya ba a kan girma na bayani kamar da ganewa molarity, yayin da nauyin da sauran ƙarfi.

Janar bayani game da mafita da kuma solubility

Gaskiya bayani kira kama tsarin, wanda ya hada da a cikin abun da ke ciki da dama aka gyara, m daga juna. Daya daga cikinsu shi ne da sauran ƙarfi, da sauran su abubuwa narkar da shi. A sauran ƙarfi da aka dauke su dũkiyõyinsu a cikin bayani da ya fi.

Solubility - wani abu tare da wasu abubuwa samar da wata kama tsarin - mafita a cikin abin da shi ne a cikin nau'i na mutum kwayoyin halitta, ions, kwayoyin ko barbashi. A taro - da mudu na solubility.

Saboda haka, da solubility abubuwa ne da ikon da za a rarraba gaba ɗaya a cikin nau'i na firamare barbashi a ko'ina cikin girma da sauran ƙarfi.

Gaskiya mafita suna classified kamar haka:

• da irin sauran ƙarfi - ba mai ruwa-ruwa da kuma ruwan.
• da irin solute - gas mafita, acid, alkalis, salts, da dai sauransu.;
• domin hulda da wani lantarki yanzu - Wutan (abubuwa da suke da lantarki watsin) da kuma wadanda ba Wutan (abubuwa ba su iya lantarki watsin).
• na taro - diluted da kuma mayar da hankali.

A taro da kuma wajen ta magana

Maida hankali kira abun ciki (nauyi) na wani abu narkar da a wasu adadin (nauyi ko girma) da sauran ƙarfi, ko a wani ayyana girma na jimlar bayani. Sai ya faru da wadannan iri:

1. A taro na sha'awa (da aka bayyana a%) - ya gaya yadda da yawa grams na solute kunshe ne a cikin 100 grams na bayani.

2. matauni taro - shi ne yawan gram moles da 1 lita na bayani. Yana nuna yadda mutane da yawa gram-kwayoyin kunshe ne a cikin 1 lita na bayani daga dũkiyar.

3. A al'ada maida hankali - shi ne yawan gram-equivalents da 1 lita na bayani. Yana nuna yadda mutane da yawa dauke da gram equivalents na wani solute a 1 lita na bayani.

4. molal taro ya nuna yadda mutane da yawa moles na solute a cikin adadin da 1 kilogram na sauran ƙarfi.

5. Titer kayyade ciki (a cikin grams) na solute narkar da a 1 milliliter na bayani.

Matauni da molal yawa daban-daban daga juna. La'akari da su mutum halaye.

A matauni taro

A dabara domin kayyade shi:

CV = (v / V), a cikinsa

v - yawan abubuwa narkar mol.

V - total girma na bayani lita ko ^M3.

Alal misali, "0.1 M bayani daga H ₂ SO _4" ya nuna cewa a cikin 1 lita na wannan bayani ne m 0.1 mol (9.8 g) na sulfuric acid .

molal taro

Ya kamata ka ko da yaushe la'akari da cewa da molal da matauni yawa da mabanbanta ma'ana.

Mene ne molal taro na bayani? A dabara domin kayyade shi ne:

Cm = (v / m), inda

v - yawan abubuwa narkar mol.

m - taro na sauran ƙarfi, kg.

Alal misali, rikodin 0,2 M NaOH bayani yana nufin cewa a 1 kilogram na ruwa (a wannan yanayin, shi ne sauran ƙarfi) rushe 0.2 mol NaOH.

Ƙarin dabarbari zama dole ga lissafin

Mutane da yawa karin bayani zai iya bukata domin molal taro da aka lasafta. Formula, wanda zai iya zama da amfani ga warware babban matsaloli su ne kamar haka.

Used adadin abu ν yi wani yawan sunadaran, electrons, kwayoyin, ions ko wasu barbashi shi.

v = m / M = N / N A = V / V m, inda:

• m - taro na fili, g ko kg.
• M - matauni taro, g (ko kg) / mol.
• N - yawan tsarin raka'a;
• N _A - yawan tsarin raka'a ta 1 mole na wani abu, Avogadro m: ^6,02. Oktoba ²³ mol ^{- 1.}
• V - a total girma na l ko m ^3;
• V _m - matauni girma, lita / mole ko ^M3 / mol.

Last lasafta kamar haka:

V _m = RT / P, inda

• R - m 8,314 J / (mol ^K.).
• T - gas zazzabi, K;
• P - gas matsa lamba Pa.

Misalai na makasudin molarity da molality. aiki №1

Don sanin matauni taro na potassium hydroxide bayani a wani juz'i daga 500 ml. The nauyi Koh bayani ne daidai da 20 grams.

definition

Matauni taro na potassium hydroxide ne:

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

Muna sa ran yawa potassium hydroxide yana kunshe ne a cikin bayani:

ν (Koh) = m / M = 20/56 = 0,36 mole.

Mun yi la'akari da cewa juz'i na bayani da za a bayyana, a lita:

500 ml = 500/1000 = 0.5 lita.

Ƙayyade da matauni taro na potassium hydroxide:

CV (Koh) = v (Koh) / V (Koh) = 0,36 / 0,5 = 0,72 mol / lita.

aiki №2

Abin da sulfur oxide (IV) a karkashin al'ada yanayi (Ina nufin, idan P = 101325 Pa, da kuma T = 273 K) ya yi domin shirya wani sulfurous acid bayani tare da wani taro na 2.5 mol / lita na girma na 5 lita?

definition

Mun ayyana a matsayin sulfurous acid dauke a cikin bayani:

ν (H ₂ SO ₃₎ = CV (H ₂ SO ₃₎ ∙ V (bayani) = 2,5 ∙ 5 = 12.5 mol.

Jadawalin samu na sulfurous acid yana da wadannan nau'i:

SO ₂ + H ₂ Ya = H ₂ SO ₃

A cewar wannan:

ν (SO ₂₎ = ν (H ₂ SO _3);

ν (SO ₂₎ = 12.5 mol.

Qazanta tuna cewa a karkashin al'ada yanayi na 1 mole na gas yana da wani ƙarfi daga 22,4 lita, ƙarar gaba da oxide da sulfur:

V (SO ₂₎ = ν (SO ₂₎ ∙ 22,4 = 12,5 ∙ 22,4 = 280 lita.

aiki №3

Don sanin matauni taro na NaOH a cikin bayani a lokacin da ta nauyi sulusi da murabba'i, daidai da 25,5%, da kuma wani yawa na 1.25 g / ml.

definition

Yarda da matsayin da samfurin bayani a wani juz'i na 1 lita da kuma sanin da taro:

m (bayani) = V (bayani) ∙ P (bayani) = 1000 ∙ 1,25 = 1,250 gram.

Muna sa ran da yawa daga cikin samfurin da nauyi Alkali:

m (NaOH) = (w ∙ m (bayani)) / 100% = (25,5 ∙ 1250) / 100 = 319 grams.

Matauni taro na sodium hydroxide daidaita:

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

Muna sa ran a matsayin sodium hydroxide yana kunshe ne a cikin samfurin:

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

Ƙayyade da matauni taro na Alkali:

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

aiki №4

A ruwa (100 grams) da aka narkar da 10 grams na gishiri NaCl. Saita maida hankali bayani (molality).

definition

A matauni taro na NaCl ne daidai to:

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

Number NaCl, dauke a cikin bayani:

ν (NaCl) = m / M = 10/58 = 0,17 mole.

A wannan yanayin, da sauran ƙarfi ne ruwa:

100 grams na ruwa = 100/1000 = 0.1 kg H ₂ Ya a cikin bayani.

Molal taro na bayani zai zama daidai:

Cm (NaCl) = v (NaCl) / m (ruwa) = 0,17 / 0,1 = 1,7 mol / kg.

aiki №5

Ƙayyade da molal maida hankali a 15% NaOH Alkali bayani.

definition

15% Alkali bayani yana nufin cewa kowane 100 grams na bayani ƙunshi 15 grams na NaOH da kuma 85 grams ruwa. Ko da a cikin kowane 100 kilo bayani yana 15 kg NaOH da 85 kg ruwa. Domin shirya shi, shi ne zama dole a 85 grams (kilo) H ₂ Ya narkar da 15 grams (kg) Alkali.

Matauni taro ne sodium hydroxide:

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

Yanzu za mu sami adadin sodium hydroxide a cikin bayani:

ν = m / M = 15/40 = 0.375 mol.

Weight sauran ƙarfi (ruwa) a kg:

85 grams na H ₂ Ya = 85/1000 = 0.085 kg H ₂ Ya a cikin bayani.

Sa'an nan Ya ƙaddara molal taro:

Cm = (ν / m) = 0.375 / 0.085 = 4,41 mol / kg.

A daidai da wadannan hankula matsala za a iya warware, kuma mafi yawan sauran domin sanin molality da molarity.