Chemical Analysis PDF

# Chemical Analysis ## Qualitative - Identification of presence or absence of each element in the sample ## Quantitative - Determination of the amount (Conc) of each element in the sample * **Types of Quantitative Analysis** * Volumetric * Gravimetric * Instrumental * **Types of Vol...

# Chemical Analysis ## Qualitative - Identification of presence or absence of each element in the sample ## Quantitative - Determination of the amount (Conc) of each element in the sample * **Types of Quantitative Analysis** * Volumetric * Gravimetric * Instrumental * **Types of Volumetric Analysis** * *1. Neutralization Reaction (Acid-Base)* - Acid + Base -> Salt + Water * *2. Precipitation Reaction* - NaCl + AgNO3 -> AgCl + NaNO3 - Reaction between two soluble salts to form third insoluble salt * *3. Compleximetric Reaction* - Ligand + Metal Ion -> Complex - Lone Pair أي مادة فيها أيون فلز فارغ من الإلكترونات. - *ex: (OH) ≤ H2O* - Ligand Metal Ion -> Complex - رابطة تناسقية Coordinate band. * *4. Oxidation-Reduction Reaction (Redox RX)* - Oxidation: Process of loss of e - Fe+2 -> Fe+3 + e - Reduction: Process of gain of e - Cl2 + 2e -> 2Cl- - Oxidizing Agent (Oxident) عامل مؤكسد: Substance has the ability to gain-e and undergo reduction process. - Reducing Agent (Reductant) عامل مختزل: Substance has the ability to loss e and undergo oxidation process. * **Theory of Volumetric Analysis** - سحاحة Burette -> Standard Solution محلول معلوم التركيز مجهول الحجم - فلاسكة Conical Flask -> Indicator كاشف -> Test Solution محلول معلوم الحجم مجهول التركيز * **Key Equations** - no- of gm equivalent Standard Solution = no of gm equivalent of test solution - Standard C.V = C.V Test قانون التحليلية ### Basic Definitions تعريفات هامة: 1. **Titration Process:** It's a gradual addition of Standard solution from Burette to a known volume of test solution till end point at which no. of gm equivalent Standard solution reacts with no. of gm equivalent of test solution. 2. **Standard Solution:** It's a solution of known Conc. - Primary... - Secondary * **Conditions of Primary Standard Solution** 1. Very pure or easily purified 2. Have high molecular weight 3. Easily soluble in H2O 4. Stable (doesn't absorb H2O, O2) 5. Available 3. **Test Solution:** Solution of known volume and unknown Conc 4. **Indicator:** Weak organic acid or weak organic base that change their color according to (pH) medium. *Examples:* Phenol Phthaliene (Ph-Ph) Methyl-orange (M-O) - Structure - Ph-Ph - M-O - Acidic: Colorless, Neutral: Colorliss, Basic: Pink, pH: 8-10 - Acidic: Red, Neutral: Orange, Basic: Yellow, pH: 3-4.4 5. **End Point:** It's a practical observed point at which the indicator changes their color and equivalent amount of standard solution equal to equivalent amount of test solution also represents the completeness of the reaction. * **Concentration Units** وحدات التركيز 1. **Molarity:** No. of moles of solute dissolved in 1L of solution - M = No. of moles = M.wt/ VL = M.wt / VL 2. **Molality:** No. of moles per kilogram of solvent 3. **Normality:** No. of gm equivalent of solute dissolved in 1L of solution - N = No. of gm equivalents/ VL = wt / eq.wt *1/VL - eq.wt = M.wt/n on حسب طبيعة المادة 4. **Strength:** No. of grams of solute dissolved in 1L of solution. - S = M * M.Wt - S = N * eq.wt أهم قانون: * **Notes for Calculating (n)** - For acid: No. of protons(H+). - For base: No. of OH groups. - For salt: According to the salt's charge (X) *valence*. - *ex: Na2SO4, n=2, NaCl, n=1, Na3PO4, n=3* - For (Redox): No. of e gain or loss - *ex: Fe+2 -> Fe+3 + e* - For gas: The amount of H that is *added* to form the compound. - *ex: NH3 + H2O -> NH4OH, n=1* - *ex: CO2 + H2O -> H2CO3, n=2*