Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water NaOH(aq) + HClaq → NaCl(aq) + H2O(l) Variables Independent The independent variable of the experiment was the amount of sodium hydroxide that we added to the acid. To keep the variable controlled we would measure 1 ml of the sodium hydroxide and pouring that to the hydrochloric acid. Dependent The dependent variables of the experiment were the temperature and the pH number of the mixture. To control the pH and temperature use the electronic probe and data logger. Controlled The controlled variables of the experiment were: A.
Neutralization Osaji Obi 3/28/2013 Introduction The objective of this experiment is to determine the neutralization curves for weak monoprotic and polyprotic acids, and to learn potentiometric pH measurement. Pka is also needed to be determined by the equation of –log(Ka). To find that we use half neutralization and titration with a strong acid. Procedure The solution is diluted to the mark with distilled water. A burette with the standardized NaOH solution is filled.
Experiment #14- Using Spectrophotometry to determine the equilibrium constant for Bromothymol Blue Chemistry 112-451 Amin,Sam* ; Clark,Kat (Lab partner) Introduction It is an important concept to understand the principles of chemical equilibrium. The concepts that are presented would be constants (K_a) and (pK_a). This experiment demonstrated the reversible reaction between Bromothymol blue and water using spectrophotometry. Materials and Methods The first step was to prepare the phosphate buffer solution. .40g of NaH_2PO_4, and .40g of Na_2HPO_4 was measured into a 150 mL beaker.
Purpose: The purpose of this lab is to verify Hess’s Law of Additivity of Reaction Enthalpies Chemical Reaction/Physical Reaction: 1.) Na(aq) + OH(aq) -> NaOH(s) 2.) NaOH + HC2H3O2(aq) -> H2O(l) + Na(aq) + C2H3O2 3.) Na(aq) + OH(aq) + HC2H3O2(aq) -> H2O(l) + Na(aq) + C2H3O2 List of Materials:Digital Thermometer, foamed polystyrene cups (3), 250 mL beaker,Weighing boat or small beaker, Graduated cylinders, 100mL(1), 25 mL(2),sodium hydroxide pellets, sodium hydroxide 2.0M, Acetic acid 1.0M and 2.0M. Safety Considerations: Always have safety goggles covering your eyes, do not inhale the fumes of chemicals used.
Step 2. Begin distillation. Right-click on the flask, and select 50 mL of crude oil from the Chemicals Window. Right-click on the flask, and select Chemical Properties. Record the grams of gasoline, kerosene, and lubricating oils that are present in the 50 mL of crude oil.
Introduction The purpose of this lab is to determine the normality of an unknown base using a volumetric titration. The volumetric titration used for this experiment consisted of a standard acid called potassium hydrogen phthalate (KHC8H4O4) titrated with a weak unknown base. An acid-base indicator called phenolphthalein is used in order to view the reaction proceeding to completion. The indicator allows visualization of the acid changing colour when the solution has reached the end point. The normality of the unknown base is calculated after the solution has reached the end point.
From these equilibrium concentrations, the equilibrium constant for the reaction can be determined. The purpose of this experiment is to determine the equilibrium constant for the following hydrolysis of an ester reaction: CH3COOCH2CH3 (aq) + H2O (l) CH3CH2OH (aq) + CH3COOH (aq) Ethyl Acetate Water Ethanol Acetic Acid (EtAc) (EtOH) (HAc) The equilibrium constant, Kc, for the reaction will have the following expression: Several reaction mixtures will be prepared with different initial amounts of ethyl
The indicator Phenolphthalein was the substance used to signal when the titration reached the point at which the reactants are stoichiometrically equal as defined by the balance reaction equation. Phenolphthalein is a chemical compound with the formula C₂₀H₁₄O₄ and is often written as "HIn" or "phph" in shorthand notation. Often used in titrations, it turns colorless in acidic solutions and pink in basic solutions. Sodium hydroxide or Hydrochloric acid would not have been as effective or accurate because they would have reacted with the water vapor from the air. In this lab setup, graduated cylinders or beakers were not used.
Purpose of the experiment: In the first part experiment 20 the purpose was to determine the change in pH, concentration of the acidic solutions, and the equilibrium constant for dissociation acid. By using several titrations, pH electrode, and titration plotted curves. In the second part experiment 21 the purpose was to determine the concentration of a weak acid in vinegar and to determine the equilibrium constant of the weak acid. Procedure: Prepare acidic solution Two bakers labeled on as KHP one as HCl for the first one 40ml of .05 M potassium hydrogen phthalate for the second beaker .1M HCl were added. 25 ml of HCl transferred to a beaker by using volumetric pipet the beaker labeled as beaker 1.
Each of these indicators will be used to show the various colors created when diluting the acids and bases. When measuring the dilutions 1.0 M HCl can be serially diluted from pH < 1 until its pH reaches 7.0 and 1.0 M NaOH can also be diluted from pH > 14 until it reaches 7.0. In the middle well there is just purely water because it is the most neutral substance, neither acidic nor basic. Water has Hydrogen and hydroxide ions, which helps determine if the substance is an acid or base. The acids are determined on how much H they have and bases are determined on how much they mess with the hydrogen concentration.