General Chemistry II Labs

INTRODUCTORY MATERIAL

Periodic Table

Tables of Physical Data

PRINT WORKSHEETS

Worksheets

LABORATORIES

Lab 1 - Reaction Stoichiometry
- Purpose
  
  To determine the stoichiometry of acid-base reactions by measuring temperature changes which accompany them.
- Goals
  
  To learn to use the MicroLab Interface...
- Introduction
  
  In this lab, you will be investigating reaction stoichiometry by doing a series of mixing experiments using acids and bases in different amounts...
- Equipment
  
  4 150 mL beakers, 3 50 mL graduated cylinder, 1 MicroLab Interface, 1 MicroLab Thermistor Instruction Sheet, 1 thermistor, 1 deionized water squirt bottle, 1 ring stand, 1 clamp
- Reagents
  
  60 mL 1.5 M HCl (aq), 45 mL 1.0 M H₃PO₄ (aq), 150 mL 1.5 M NaOH (aq)
- Safety
  
  You will be working with hydrochloric acid, HCl (aq); phosphoric acid, H₃PO₄ (aq); and NaOH (aq). These chemicals are corrosive...
- Waste Disposal
  
  The solutions used in this experiment can be flushed down the sink with plenty of water.
- Prior to Class
  
  Please read the following section of Lab Safety and Practices...
- Lab Procedure
  
  Open the MicroLab program. Calibrate the thermistor as described in the MicroLab instructions provided in the lab...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 2 - Solutions and Spectroscopy
- Purpose
  
  To determine the concentration of a copper sulfate (CuSO₄) solution, and to duplicate its concentration by two methods.
- Goals
  
  To learn how to use a pipet properly...
- Introduction
  
  A solution is a homogeneous mixture of two or more substances. Simple solutions consist of one solvent and one or more solutes...
- Equipment
  
  1 MicroLab Spectrophotometer, 1 MicroLab Spectrophotometer Instruction Sheet, 6 vials, 2 Serological pipets, 1 pipet bulb...
- Reagents
  
  25 mL 0.5XX M CuSO₄ (aq) stock solution, 5 drops CuSO₄ (aq) unknown solution, 1 g solid CuSO₄ · 5 H₂O
- Safety
  
  CuSO₄ · 5 H₂O is listed as toxic and an irritant. Toxic substances are hazardous to health when breathed, swallowed or in contact with the skin...
- Waste Disposal
  
  Solutions containing copper ions must be placed in the waste bottle in the lab. Designate a "waste copper" beaker and set it aside for use during your lab...
- Prior to Class
  
  Please read the following section of Lab Safety and Practices...
- Lab Procedure
  
  A spectrophotometer will be set up in your work area. Make sure it is turned on and allow it to warm up...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 3 - Freezing Point Depression
- Purpose
  
  To predict and measure the freezing point depression caused by a solute in a solvent.
- Goals
  
  To learn to accurately measure a freezing point depression for a solution...
- Introduction
  
  A solution is a homogeneous mixture of two or more substances. For the common two-component solution, the substance present in the major proportion is called the solvent and that in the minor proportion is called the solute...
- Equipment
  
  1 crystallization dish, 1 100 mL graduated cylinder, 1 30 mL beaker, 1 digital thermometer, 1 tongs, 1 spatula, 1 hot plate
- Reagents
  
  ~9 g stearic acid, ~2 g lauric acid
- Safety
  
  Stearic acid and lauric acid are nonhazardous, but prolonged contact with skin may cause irritation...
- Waste Disposal
  
  Stearic and lauric acid solutions should be placed in the labeled waste container in the lab. Solid may be warmed in a hot water bath so that it can be poured into the waste container...
- Prior to Class
  
  Please read the following section of Lab Safety and Practices...
- Lab Procedure
  
  Prepare a hot water bath in your crystallization dish by heating about 85 mL of tap water on your hot plate (~1/2 filled)...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 4 - Calorimetry
- Purpose
  
  To determine if a Styrofoam cup calorimeter provides adequate insulation for heat transfer measurements, to identify an unknown metal by means of its heat capacity and to determine a heat of neutralization and a heat of solution.
- Goals
  
  To perform simple calorimetry experiments. To use calorimetry results to calculate the specific heat of an unknown metal...
- Introduction
  
  Heat and work are the two most common ways for a system to exchange energy with its surroundings...
- Equipment
  
  1 400 mL beaker, 2 Styrofoam cups with lid, 1 18 × 150 mm test tube, 1 test tube holder, 1 150 mL beaker, 1 250 mL beaker, 1 50 mL beaker, 2 100 mL graduated cylinders, 1 hot plate...
- Reagents
  
  ~20 g metal unknowns, ~50 mL 1.5 M NH₃, ~50 mL 1.5 M H₃PO₄, ~10 g NH₄H₂PO₄, deionized water
- Safety
  
  Phosphoric acid is corrosive. It can attack the skin, cause permanent damage to the eyes, and cause burns...
- Waste Disposal
  
  All solutions may be flushed down the sink with plenty of water. Do not put the metal samples in the sink...
- Prior to Class
  
  Please review the following video: Safety...
- Lab Procedure
  
  Start the MicroLab Interface and calibrate the thermistor as described in the MicroLab instructions provided in the lab...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 5 - Determination of an Equilibrium Constant
- Purpose
  
  To determine the equilibrium constant for the reaction...
- Goals
  
  To gain more practice using a pipet properly. To gain more practice diluting stock solutions...
- Introduction
  
  A typical chemical equation has the following form: aA + bB → cC + dD...
- Equipment
  
  1 MicroLab Spectrophotometer, 1 MicroLab Spectrophotometer Instruction, 6 vials, 3 Serological pipets, 1 pipet bulb, 3 30 mL beakers for reagents, 6 13 × 100 mm test tubes for mixtures...
- Reagents
  
  ~10 mL 0.100 M Fe(NO₃)₃ in 0.2 M HNO₃, ~10 mL 5.00 × 10⁻⁴ M NaSCN in 0.2 M HNO₃, ~15 mL 0.002 M Fe(NO₃)₃ in 0.2 M HNO₃...
- Safety
  
  Nitric acid is listed as a corrosive. Corrosives can attack the skin and cause permanent damage to the eyes...
- Waste Disposal
  
  All of the solutions prepared in this experiment, as well as excess NaSCN solution, should be discarded in the waste container...
- Prior to Class
  
  Please read the following section of Lab Safety and Practices...
- Lab Procedure
  
  A spectrophotometer will be set up in your work area. Make sure it is turned on and allow it to warm up... ...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 6 - Electrochemical Cells
- Purpose
  
  To see how changes in concentration and pH affect the potential in an electrochemical cell, and confirm the Nernst equation.
- Goals
  
  To examine how standard reduction potentials are measured...
- Introduction
  
  A galvanic cell is an electrochemical cell in which the spontaneous electrochemical reaction proceeds, that is, DeltaG for the reaction is negative...
- Equipment
  
  1 MicroLab Interface, 1 voltmeter alligator clip leads, 1 400 mL beaker for rinsings, 1 100 mL beaker, 1 salt bridge assembly...
- Reagents
  
  100 mL 0.1 M Zn(NO₃)₂ (in covered plastic container), 100 mL 0.1 M Cu(NO₃)₂ (in covered plastic container), 100 mL 0.1 M AgNO₃ (in covered plastic container)...
- Safety
  
  3 M HCl solution gives off highly irritating vapors. Do not inhale them. Work with concentrated solutions under the hood so vapors do not build up in the lab...
- Waste Disposal
  
  Test solutions that are provided in plastic containers in which measurements are to be made should not be discarded...
- Prior to Class
  
  Please read the following section of Lab Safety and Practices...
- Lab Procedure
  
  Open the MicroLab program. Make sure the alligator clip leads are connected to the interface...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab......
Lab 7 - Mixtures of Acids and Bases
- Purpose
  
  To investigate the resulting pH's of different mixtures of acid and base solutions.
- Goals
  
  To calculate the pH of pure acid and base solutions. To calculate the pH of mixtures of acid and base solutions...
- Introduction
  
  Brønsted acids are defined as proton donors. When placed in water, Brønsted acids (HA) donate a proton to water to produce the conjugate base of the acid (A⁻) and a hydronium ion (H₃O⁺) according to the following reaction...
- Equipment
  
  1 25 × 150 mm test tube, 1 400 mL beaker (to hold the test tube), 1 glass stir rod, 1 10 mL graduated cylinder, 1 100 mL beaker, 2 30 mL beakers, 1 MicroLab Interface, 1 MicroLab pH Measurement Instruction Sheet...
- Reagents
  
  ~60 mL 0.1 M NaOH, 10 mL, 0.1 M HCl, 10 mL 0.1 M NH₄Cl, 10 mL 0.1 M NaC₂H₃O₂...
- Safety
  
  HCl and NaOH are corrosive. They can attack the skin and cause permanent damage to the eyes...
- Waste Disposal
  
  All solutions can be flushed down the sink with plenty of water.
- Prior to Class
  
  Please complete your WebAssign prelab assignment. Check your WebAssign account for due dates...
- Lab Procedure
  
  In this experiment, you will be using pH electrodes connected to the MicroLab Interface. pH electrodes have a thin glass bulb at the tip...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 8 - Buffers
- Purpose
  
  To prepare buffers and measure the pH of each, and to prepare a buffer at a specific pH.
- Goals
  
  To learn to prepare buffers by both the direct and indirect methods. To learn to identify solutions that are buffers...
- Introduction
  
  In dilute aqueous solutions, weak acids are slightly dissociated. They produce a small concentration of hydronium ion (H₃O⁺) and an equal concentration of the conjugate base of the acid...
- Equipment
  
  2 30 mL beakers, 2 100 mL volumetric flasks, 1 10.0 mL volumetric pipet, 1 pipet bulb, 1 50 mL graduated cylinder, 1 10 mL graduated cylinder...
- Reagents
  
  ~10 mL 6.0 M acetic acid (HC₂H₃O₂), <10 g solid sodium acetate trihydrate (NaC₂H₃O₂ · 3 H₂O), ~25 mL 1.0 M NaOH...
- Safety
  
  Acetic acid, HCl and NaOH are corrosive. They can attack the skin and cause permanent damage to the eyes...
- Waste Disposal
  
  All solutions can be flushed down the sink with water.
- Prior to Class
  
  Please read the following section of Lab Safety and Practices...
- Lab Procedure
  
  In this experiment, you will be using pH electrodes connected to the MicroLab Interface. pH electrodes have a thin glass bulb at the tip...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 9 - Titration Curves
- Purpose
  
  To determine the equivalence points of two titrations from plots of pH versus mL of titrant added.
- Goals
  
  To gain experience performing acid-base titrations with a pH meter. To plot titration curves of pH vs mL of titrant added...
- Introduction
  
  A titration is an analytical procedure in which a reaction is run under carefully controlled conditions...
- Equipment
  
  1 MicroLab Interface, 1 MicroLab pH Measurement Instruction Sheet, 1 pH electrode in pH 7.00 buffer, 2 30 mL beakers...
- Reagents
  
  ~25 mL 0.20 M potassium hydrogen phthalate (KHP), ~30 mL 0.20 M sodium hydroxide (NaOH), 3 drops phenolphthalein solution...
- Safety
  
  Potassium hydrogen phthalate is listed as an irritant. Sodium carbonate is listed as both toxic and an irritant...
- Waste Disposal
  
  All solutions can be flushed down the sink with plenty of water.
- Prior to Class
  
  Please read the following sections of the Introductory Material...
- Lab Procedure
  
  In this experiment, you will be using pH electrodes connected to the MicroLab Interface. pH electrodes have a thin glass bulb at the tip...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 10 - Solubility Product Constants
- Purpose
  
  To measure the solubility product constant (K_sp) of copper (II) iodate, Cu(IO₃)₂.
- Goals
  
  To measure the molar solubility of a sparingly soluble salt in water. To prepare a calibration curve based on complex ion formation for absorbance enhancement...
- Introduction
  
  In previous introductory chemistry courses, you learned some basic solubility rules that are useful in determining if an ionic solid will dissolve in water...
- Equipment
  
  15 13 × 100 mm test tubes, 5 stoppers, 1 test tube rack, 1 spatula, 1 glass stir rod, 1 MicroLab Spectrophotometer, 1 MicroLab Spectrophotometer Instruction Sheet, 6 vials, ...
- Reagents
  
  ~0.25 g solid Cu(IO₃)₂, ~5 mL 5.0 × 10⁻⁴ M Cu(NO₃)₂, ~10 mL 1.0 × 10⁻³ M Cu(NO₃)₂, ~10 mL 5.0 × 10-3 M Cu(NO₃)₂...
- Safety
  
  Cu(NO₃)₂ is listed as an oxidizer and corrosive. KIO₃ and Cu(IO₃)₂ are listed as strong oxidizing agents...
- Waste Disposal
  
  All solutions generated this week must be placed in the waste bottle in the lab. Designate a "waste" beaker and set it aside for use during your lab...
- Prior to Class
  
  Please read the following sections of the Introductory Material...
- Lab Procedure
  
  A spectrophotometer will be set up in your work area. Make sure it is plugged in and allow it to warm up...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.
Lab 11 - Chemical Kinetics
- Purpose
  
  To determine the rate law for the reaction 2 I⁻ + S₂O₈²⁻ → I₂ + 2 SO₄²⁻.
- Goals
  
  To relate changes in reactant concentrations to changes in reaction rate. To calculate a rate constant from experimental data.
- Introduction
  
  Chemical kinetics deals with the speed, or rate, of a reaction and the mechanism by which the reaction occurs. We can think of the rate as the number of events per unit time...
- Equipment
  
  2 50 mL burets, 2 50 mL graduated cylinders, 4 100 mL beakers, 4 50 mL beakers, 1 magnetic stir plate, 1 magnetic stir bar...
- Reagents
  
  ~90 mL 0.200 M KI, ~90 mL 0.100 M (NH₄)₂S₂O₈, ~60 mL 0.0050 M Na₂S₂O₃, ~30 mL 0.200 M KCl...
- Safety
  
  Sodium persulfate is an oxidizing agent. Oxidizing agents can supply their own source of oxygen and may react violently with organic liquids or other reducing agents...
- Waste Disposal
  
  All of the solutions can be flushed down the sink with plenty of water.
- Prior to Class
  
  Please read the following sections of Lab Safety and Practices...
- Lab Procedure
  
  Five different solutions with similar names are used in this experiment. Label the glassware so you will not mix things up...
- Worksheet
  
  You will use a hard copy of this worksheet to enter data as you work through the experiment in lab. Print the worksheet and bring it with you to the lab.