Lab 6: Measuring CEC Use soils from last week to –

Slides:

Advertisements

Similar presentations

Soil Samples Analyses and Interpretation. PPM parts per million average weight of 6 inch soil =2 million pounds 1 ppm = 2 pounds / acre.

Advertisements

Acidity Constant by pH Titration Curves

Purpose Background - The Power of Antacids

V. Acid-Base Titration Titration is the process of adding a measured

1 Objective:The objective of this experiment is to determine the mass of acetylsalicylic acid (ASA) in an Aspirin tablet. Chemicals Potassium hydrogen.

Neutralization Reactions Reaction that occurs between an acid and a base. Example: HCl + NaOH  NaCl + H 2 O & Water Products always include: A “Salt”

Experiment 39: Analysis of Commercial Bleach Purpose Introduction: Many commercial products are effective because they contain oxidizing agents. Some products.

Lab 6: Measuring CEC Use soils from last week to – > extract exchangeable cations > measure basic cations by AA spectroscopy > measure acid cations by.

Titration burette clamp ring stand burette erlenmeyer flask.

Burette clamp ring stand burette erlenmeyer flask Titration.

1 Gravimetric Analysis 1.Dissolve unknown substance in water 2.React unknown with known substance to form a precipitate 3.Filter and dry precipitate 4.Weigh.

Acid-Base Stoichiometry

Titration Pre-lab.

Chemistry Notes: Titrations Chemistry  A titration is a lab procedure which uses a solution of known concentration to determine the concentration.

Lab 42- Analysis of asprin. Part 1  Neutralize all the asprin, and additonal acidic impurities.

Burette clamp ring stand burette erlenmeyer flask Titration.

I-Solubility Product: Acid-Base Volumetric Analysis

Titration Chemistry: The Molecular Nature of Matter, 6 th edition By Jesperson, Brady, & Hyslop acid–base, 198–199, 811–819 redox reactions, 239–240.

Topic 1.5 Titrations. Titrations In a titration a solution of accurately known concentration is added gradually added to another solution of unknown concentration.

Determination of bicarbonate in blood

Business Exam At 7:00 PM arrive early Covers chapters MC questions, 4 Fill ins, and 2 work out Time 1hr 30 min Review during Wednesday.

Solutions Solubility -the amount of solute that can be dissolved to form a solution. Solvent – the substance in a solution present in the greatest amount.

Le Châtelier’s principle. The significance of Kc values If Kc is small (0.001 or lower), [products] must be small, thus forward reaction is weak If Kc.

Initial HClFinal HCl HCl added Initial NaOH Final NaOH NaOH added Molarity of NaOH 0.00 mL1.10 mL 3.00 mL5.35 mL 0.85 mL 1.10 mL2.10 mL 1.00 mL0.77 mL.

Neutralization Reaction

What type of reaction? HCl + NaOH  H2O + NaCl

HCl (aq) + NaOH (aq)  NaCl (aq) + H2O (l)

Lab 20- Acids & Bases Titration.

5.3.1 Neutralization reactions Titration Reactions.

Phase Two Titration Year 10 EEI by Mr H Graham Volumetric analysis is; A type of chemical analysis which depends on the accurate measurement of solution.

Acid - Base Titration. What is a Titration? A titration is a procedure used in chemistry to determine the concentration of an unknown acid or base. A.

1 Titrations (Review) In a titration a solution of accurately known concentration is added gradually added to another solution of unknown concentration.

Why do Titration Curves Look Like THAT ???? 1/4/20161.

C. Johannesson III. Titration/Neutralization 18.4 Ch. 18- Acids & Bases.

Upset Stomach Lab Comparing the neutralizing power of commercial antacids.

NEUTRALIZATION, INDICATORS, AND TITRATIONS. NEUTRALIZATION REACTIONS So far we have only looked at acid and base reactions with water Ka and Kb reactions.

Objective Acids, Bases and Indicators…oh my!

Lab #10: Determining the Molar Mass of a Diprotic Acid December 2015.

Chemistry I Honors Acids Lesson #2 Behaviors and Reactions.

Titration. Using an acid (or base) of known concentration to neutralize a base (or acid) of unknown concentration. –Using the burets and indicator.

Making Salts Insoluble salts – precipitation Mix two solutions together one with the cation, one with the anion. Filter, wash and dry. Soluble Na +, K.

Lab 24Date: Acids, Bases and Indicators…oh my! Purpose Background Observe a neutralization rxn & work with indicators. Bases will turn red litmus blue.

Experiment 39: Analysis of Commercial Bleach

POINT > Review acid-base neutralization POINT > Identify pH indicators and how they work POINT > Describe titration process.

10.3 Acid- Base Stoichiometry: TITRATION. What is a titration? A procedure used to determine the concentration of a solution using a standardized solution.

Trinity College Dublin, The University of Dublin Titration Demonstration.

All you need to know to perform a strong acid-base neutralization

Titration of a Strong Base with a Strong Acid

TITRATION OF A STRONG BASE WITH A STRONG ACID

Unit 15 Acids & Bases.

Lab #6: Determining the Molar Mass and Ka1 of a Diprotic Acid

Lab #9: Determining the Molar Mass of a Diprotic Acid

Titration Introduction Experiment

Acid-Base Titration Chemists often need to know the concentration of an acidic or basic solution, and to acquire this, they use an experimental procedure.

Determining the Acidity of Soda… An Acid Base Titration

REACTIONS WITH ACIDS.

Neutralization.

Acid Base Titration.

Lab 9: Determining the Concentration of Acetic Acid in Vinegar

Determination of Soil Acidity

Acid Base Reactions HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)

EXP. NO. 6 Acid Base Titration

Procedure Notes Part 1: Making NaOH solution

Procedures Reading from the text.

Chapter 4.8 Review Acid-Base Reactions.

Acid-Base Titration. Acid-Base Titration. Acid-Base Titration.

Standardization The Titration.

Acid-Base Titration. Acid-Base Titration. Acid-Base Titration.

Neutralization reactions

Presentation transcript:

Lab 6: Measuring CEC Use soils from last week to – > extract exchangeable cations > measure basic cations by AA spectroscopy > measure acid cations by titration > calculation CEC, % BS for your soil > convert from meq/100g to lbs/acre

Procedure: Weigh 3.0 g soil into 50 mL centrifuge tube 2. Pump in 35 mL NaCl extracting solution 3. Shake for 20 minutes to displace exchangeable cations from colloid surface into solution…

Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Ion Exchange by Mass Action Added Na soln … Mg+2 Ca+2 K+ Al+3 Displaced cations

Measurement of exchangeable cations: 1. Centrifuge, filter to separate clear solution. 2. Fill glass vial about ½ full of solution for AA analysis. 3. Measure remaining solution using grad cylinder—record this number, this will be your “volume titrated”. Pour back into Erlenmeyer flask.

Titration of exchangeable acids: To Erlenmeyer flask: add stir bar and 3-4 drops phenolpthalein indicator , turn on stirrer to slow speed. Add NaOH from burette SLOWLY (drop by drop) until solution stays pink for 20-30 seconds. Record volume base used from burette. At endpoint: pH is near neutral, and AMT BASE ADDED = AMT ACID PRESENT NB x VB = NA x VA

Titration calculations: NB x VB = NA x VA NB: conc of base: 0.005 N (eq/L = meq/mL) VB: volume of base (mL, burette) VA: volume of acid (“mLs titrated”) NA: conc of acid: UNKNOWN… meq acid/mL

Conc (solution)  Conc (soil) We used 35 mL of NaCl solution to extract 3 g soil to get cations into solution…. Meq acid x 35 mL soln x 100 = meq acid mL soln 3 g soil 100 100 g soil Same for basic cations by AA: Meq Ca x 0.035 L soln x 100 = meq Ca L soln 3 g soil 100 100 g soil

CEC of soil =  cations (in meq/100 g): Ca + Mg + K + acidity (H+Al) Mg and K: written on board (meq/L)….. % base saturation (BS) =  bases (Ca+Mg+K)/CEC Convert meq/100 g into lbs/acre-furrow slice….

CEC calculations: meq/100 g to lbs/acre Assume a soil has 2 meq K+/100 g: how many lbs/acre? (“acre” = acre-furrow slice= 2x106 lbs) Note: Atomic mass of K=39 g/mole, and 1mol=1equiv (K+1) So-- Now: “mg/kg” is PPM = parts per million… and LBs/AFS = lbs/2x106 lbs, which is “parts per 2 million”…. SO: 780 ppm K x 2 = 1560 lbs K/acre