Piv txwv cov lus nug thiab kev sib tham: Cov Qauv Molecular thiab Cov Qauv Empirical
Kev kawm txog chemistry yog ib qho tseem ceeb uas yuav tsum kawm txog cov ntsiab lus tseem ceeb xws li cov qauv molecular thiab cov qauv empirical. Ob lub ntsiab lus no tseem ceeb heev vim lawv muab kev nkag siab txog cov tshuaj sib xyaw ua ke. Tsab xov xwm no yuav tshawb nrhiav cov teeb meem piv txwv thiab tham txog lawv. Yog koj nkag siab zoo txog ob lub ntsiab lus no, vam tias koj yuav pom tias nws yooj yim dua los daws cov teeb meem chemistry, tshwj xeeb tshaj yog cov uas nyob hauv tshooj no.
Nkag Siab Txog Cov Qauv Empirical
Ib daim qauv empirical yog ib daim qauv uas qhia txog qhov sib piv yooj yim tshaj plaws ntawm cov atoms uas ua rau ib qho compound. Daim qauv no tsis qhia txog tus lej tseeb ntawm cov atoms hauv ib lub molecule, tab sis tsuas yog qhov sib piv me tshaj plaws ntawm cov atoms ntawd. Piv txwv li, daim qauv empirical rau glucose yog CH₂O, uas txhais tau tias hauv ib lub molecule ntawm glucose muaj qhov sib piv ntawm ib lub carbon atom rau txhua ob lub hydrogen atoms thiab ib lub oxygen atom.
Kev Nkag Siab Txog Cov Qauv Molecular
Lub caij no, cov mis molecular muab cov ntaub ntawv hais txog tus lej tiag tiag ntawm txhua lub ntsiab lus hauv ib lub molecule ntawm ib qho compound. Piv txwv li, cov mis molecular rau glucose yog C₆H₁₂O₆, txhais tau tias txhua lub molecule glucose muaj rau lub carbon atoms, kaum ob lub hydrogen atoms, thiab rau lub oxygen atoms.
Cov Kauj Ruam Los Txheeb Xyuas Cov Qauv Empirical
1. Txheeb Xyuas Qhov Hnyav ntawm Txhua Yam Khoom: Yog tias muab feem pua ntawm qhov hnyav, ua ntej txiav txim siab qhov hnyav ntawm txhua yam khoom hauv 100 grams ntawm cov khoom sib xyaw.
2. Hloov Qhov Loj mus rau Moles: Hloov qhov loj ntawm ib yam khoom mus rau moles los ntawm kev faib qhov loj los ntawm qhov loj molar ntawm txhua yam khoom.
3. Txheeb Xyuas Qhov Sib Piv ntawm Mole: Txheeb xyuas qhov sib piv ntawm mole ntawm cov ntsiab lus uas muaj. Txoj kev no yog faib tus lej ntawm moles ntawm txhua lub ntsiab lus los ntawm tus lej me tshaj plaws ntawm moles tau txais.
4. Kev Sib Piv: Yog tias tsim nyog, kev sib piv mole mus rau tus lej tag nrho ze tshaj plaws.
5. Sau Cov Qauv Siv Los Ntawm Kev Paub Tseeb: Muab cov kev sib piv no ua ke los sau cov qauv siv los ntawm kev paub tseeb.
Cov Kauj Ruam Los Txheeb Xyuas Cov Qauv Molecular
Yuav kom txiav txim siab tau cov mis molecular, peb xav tau qhov hnyav molar ntawm cov tshuaj thiab nws cov mis empirical. Nov yog cov kauj ruam dav dav:
1. Txheeb Xyuas Tus Qauv Empirical: Ua cov kauj ruam los txiav txim siab tus qauv empirical ua ntej.
2. Xam Qhov Molar Mass ntawm Empirical Formula: Ntxiv cov molar mass ntawm txhua lub ntsiab lus hauv cov empirical formula kom tau txais molar mass ntawm cov empirical formula.
3. Kev Txheeb Xyuas Qhov Mole Mass ntawm Ib Lub Compound: Feem ntau muab rau hauv cov lus nug lossis kev sim.
4. Txheeb xyuas N Factor: Faib qhov mole mass ntawm cov compound los ntawm molar mass ntawm cov mis empirical kom tau txais qhov factor (n).
5. Txheeb Xyuas Cov Qauv Molecular: Muab tus lej (n) sib npaug los ntawm tag nrho cov ntawv sau hauv cov qauv empirical kom tau txais cov qauv molecular.
Cov Lus Nug Piv Txwv thiab Kev Sib Tham
Lo lus nug 1: Kev txiav txim siab ntawm Empirical Formula
Ib qho tshuaj muaj cov qauv sib xyaw ua ke no: 40% carbon (C), 6,7% hydrogen (H), thiab 53,3% oxygen (O). Txheeb xyuas cov mis empirical ntawm cov tshuaj no.
Lus teb:
1. Hloov Mass mus rau Moles:
- Cov pa roj carbon:
\[
\frac{40 g}{12 g/mol} = 3,33 mol
\]
- Hydrogen:
\[
\frac{6,7 g}{1 g/mol} = 6,7 mol
\]
- Cov pa oxygen:
\[
\frac{53,3 g}{16 g/mol} = 3,33 mol
\]
2. Txheeb xyuas qhov sib piv ntawm Mole:
– C: 3,33 mol / 3,33 = 1
– H: 6,7 mol / 3,33 = 2
– O: 3,33 mol / 3,33 = 1
3. Sau Cov Qauv Empirical:
- Qhov piv ntawm mole ntawm C:H:O yog 1:2:1, yog li cov mis empirical yog CH₂O.
Lo Lus Nug 2: Kev Txheeb Xyuas Cov Qauv Molecular
Yog tias qhov hnyav ntawm cov tshuaj uas muaj cov mis empirical CH₂O paub tias yog 180 grams / mol, txiav txim siab nws cov mis molecular.
Lus teb:
1. Qhov hnyav ntawm cov mis empirical CH₂O:
– Molar mass C = 12 g/mol
– Molar mass H = (2 x 1) g/mol = 2 g/mol
– Molar mass ntawm O = 16 g/mol
Yog li ntawd, qhov hnyav ntawm CH₂O = 12 + 2 + 16 = 30 g/mol
2. Txheeb xyuas tus n factor:
\[
\frac{qhov hnyav ntawm molar}{qhov hnyav ntawm molar}} = \frac{180 g/mol}}{30 g/mol}} = 6
\]
3. Kev Txheeb Xyuas Cov Qauv Molecular:
- Tus n factor yog 6, yog li cov mis molecular yog 6 x (CH₂O) = C₆H₁₂O₆.
Piv txwv ntawm cov lus nug uas xav tau kev xam zauv nyuaj dua
Lo Lus Nug 3: Txheeb Xyuas Cov Qauv Empirical los ntawm Cov Ntaub Ntawv Feem Pua
Ib qho organic compound muaj 75.0% carbon, 20.0% hydrogen, thiab 5.0% nitrogen. Txheeb xyuas cov mis empirical ntawm cov compound.
Lus teb:
1. Hloov Mass mus rau Moles:
- Cov pa roj carbon:
\[
\frac{75.0 g}{12.0 g/mol} = 6.25 mol
\]
- Hydrogen:
\[
\frac{20.0 g}{1.0 g/mol} = 20.0 mol
\]
- Nitrogen:
\[
\frac{5.0 g}{14.0 g/mol} = 0.357 mol
\]
2. Txheeb xyuas qhov sib piv ntawm Mole:
C: 6.25 mol / 0.357 = 17.5 ≈ 18
– H: 20.0 mol / 0.357 = 56 ≈ 56
– N: 0.357 mol / 0.357 = 1
3. Sau Cov Qauv Empirical:
- Qhov piv ntawm mole C:H:N ≈ 18:56:1, cov mis empirical yog C₁₈H₅₆N.
Xaus
Kev nkag siab txog cov ntsiab lus ntawm cov qauv molecular thiab empirical yog qhov tseem ceeb hauv chemistry. Los ntawm kev ua raws li cov kauj ruam tau teev tseg thiab xyaum cov piv txwv uas tau muab, koj vam tias yuav dhau los ua tus kws tshaj lij hauv kev txiav txim siab cov qauv empirical thiab molecular ntawm cov tshuaj sib xyaw. Xyaum tsis tu ncua kom koj nkag siab tob ntxiv txog cov khoom siv no.
