84 Results
Hydrogen and Hydroxide Ions   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Buffer Solutions   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Conjugate Acid-Base Pairs and pH   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Hydration of Ions   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Solutions   
(Movie/Animation, Audio/Visual (9))
Reactions and demonstrations exploring the concepts of solutions.
Aqueous Reactions: Sodium Hydroxide   
(Movie/Animation, Audio/Visual (9))
Reactions of solutions with aqueous Sodium Hydroxide.
Aqueous Reactions: Sodium Carbonate   
(Movie/Animation, Audio/Visual (9))
Reactions of solutions with aqueous Sodium Carbonate.
Aqueous Reactions: Sodium Chloride   
(Movie/Animation, Audio/Visual (9))
Reactions of solutions with aqueous Sodium Chloride.
Aqueous Reactions: Hydrochloric Acid   
(Movie/Animation, Audio/Visual (9))
Reactions of solutions with aqueous Hydrochloric Acid.
Aqueous Reactions: Sulfuric Acid   
(Movie/Animation, Audio/Visual (9))
Reactions of solutions with aqueous Sulfuric Acid.
Aqueous Reactions: Copper(II) Sulfate   
(Movie/Animation, Audio/Visual (9))
Reactions of solutions with aqueous Copper (II) Sulfate.
Aqueous Reactions: Ammonia   
(Movie/Animation, Audio/Visual (9))
Reactions of solutions with aqueous Ammonia.
Aqueous Reactions: Barium Chloride   
(Movie/Animation, Audio/Visual (9))
Reactions of solutions with aqueous Barium Chloride.
Oxidation-Reduction Aqueous Solutions   
(Movie/Animation, Audio/Visual (8))
Oxidation-reduction reactions carried out in aqueous solution.
Aqueous Reactions: Zinc Nitrate   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with Zinc Nitrate.
Aqueous Reactions: Strontium Chloride   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with aqueous Strontium Chloride.
Aqueous Reactions: Lead(II) Nitrate   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with aqueous Lead (II) Nitrate.
Aqueous Reactions: Nickel(II) Nitrate f   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with aqueous Nickel (II) Nitrate.
Aqueous Reactions: Manganese (II) Chloride   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with Manganese (II) Chloride.
Aqueous Reactions: Mercury(I) Nitrate   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with aqueous Mercury (I) Nitrate.
Aqueous Reactions: Mercury(II) Ion   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with aqueous Mercury (II) Ions.
Aqueous Reactions: Iron(III) Ion   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with aqueous Iron (III) Ions.
Aqueous Reactions: Iron(II) Ion   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions with aqueous Iron(II) Ion.
Aqueous Reactions: Chromium(III) Chloride   
(Movie/Animation, Audio/Visual (8))
Reactions of solutions in aqueous Chromium (III) Chloride.
Aqueous Reactions: Cadmium Nitrate   
(Movie/Animation, Audio/Visual (8))
Reactions between various solutions and aqueous Cadmium Nitrate.
Aqueous Reactions: Silver Nitrate   
(Movie/Animation, Audio/Visual (8))
Reactions with the addition of ions in solution to aqueous silver nitrate.
Decomposition Reactions   
(Movie/Animation, Audio/Visual (6))
Various examples of decomposition reactions are presented.
Halogen-Halide Redox Reactions   
(Movie/Animation, Audio/Visual (6))
An aqueous solution of a halogen (Cl2, Br2 or I2) is poured into an aqueous halide solution (Cl-, Br- or I-) covered with a layer of hexane.
Solid Producing   
(Movie/Animation, Audio/Visual (6), Movie/Animation (1))
Electrolysis of solutions in which a solid is produced is shown.
Gas Producing   
(Movie/Animation, Audio/Visual (6), Movie/Animation (1))
Electrolysis of solutions with only gas(es) produced is shown.
Oxidation-Reduction (Redox) Reactions   
(Movie/Animation, Audio/Visual (5))
Demonstrations exploring oxidation/reduction chemistry.
Reactions in Aqueous Solutions   
(Movie/Animation, Audio/Visual (5))
Various reactions in aqueous solutions are shown.
Electrolysis   
(Movie/Animation, Audio/Visual (4))
Various examples of electrolysis are presented.
Reactions of Sulfuric Acid   
(Movie/Animation, Audio/Visual (4))
Reactions of materials reacting with sulfuric acid are shown.
Closeup Videos of Flames from Aqueous Solutions   
(Movie/Animation, Audio/Visual (4))
Aqueous solutions of common compounds are introduced via aerosol to flame, producing their characteristic emission colors.
HCl, NaOH, NaCl and Water   
(Movie/Animation, Audio/Visual (4))
Electrolysis of HCl, NaOH and NaCl solutions and of water is shown.
Acid-Base Titrations and Animation   
(Movie/Animation, Audio/Visual (4))
Videos in this group show titrations of various acids with sodium hydroxide as well as molecular reactions during titration.
Electrolysis of Aqueous Solutions -- New   
(Movie/Animation, Audio/Visual (4))
This is a revised version of the previously published Electrolysis of Aqueous Solutions, providing corrections and additional images. In order to understand most of these videos it is important to either see the Complete Experiment: Electrolysis of an Aqueous Solution video or to be able to read a description of that video (such as the one in the Discussion section for that video).
Precipitation Reactions   
(Movie/Animation, Audio/Visual (21))
Approximately 2 mL of Solution A is added to a sample of Solution B with a dropping pipet. If a precipitate forms, the resulting precipitate is supended in the mixture. The mixture is then stirred with a glass stirring rod and the precipitate is allowed to settle for about a minute.
Electrolysis of Aqueous Solutions -- Original   
(Movie/Animation, Audio/Visual (20), Movie/Animation (2))

Electrolysis of several aqueous solutions is carried out using a 9-V battery and pencil leads as electrodes. Because only the electrodes are shown in the videos, it is important to show these still images

 

or describe how the reactions were performed if students are to make sense of the videos. In each case the anode is on the left and a 9-V battery has been connected to the lead of each of the pencils near the eraser end with an alligator clip.

A newer version of most of these reactions using platinum electrodes is available as Electrolysis of Aqueous Solutions -- New.

Ammonia Fountains   
(Movie/Animation, Audio/Visual (2))
An ammonia fountain is demonstrated.
Ammonia Fountains - Multiple   
(Movie/Animation, Audio/Visual (2))
System of multiple ammonia fountains are set up and run. A separatory funnel, four round-bottomed flasks, and some tubing form a closed system. One end of the tubing is immersed in an acetic acid solution that contains universal indicator. The glassware has been filled with ammonia gas. The stopcock of the funnel is closed.
Redox Titration and Animation   
(Movie/Animation, Audio/Visual (2))
A simple redox titration (hydrogen peroxide with permanganate) is performed. Also an animation demonstrates aspects of the stoichiometry.
Redox Titration and Animation   
(Movie/Animation, Audio/Visual (2))
Videos in this group show a redox titration and the molecular changes during the titration.
Tin Compounds   
(Movie/Animation, Audio/Visual (2))
Electrolysis of tin(II) and tin(IV) solutions of different concentrations is shown.
Acid Base Reactions   
(Movie/Animation, Audio/Visual (16))
Simple experiments show the titration of acids with sodium hydroxide and the generation of acid from carbon dioxide in water.
Aqueous Reactions: Copper(II) Nitrate   
(Movie/Animation, Audio/Visual (13))
Reactions of solutions with aqueous Copper (II) Nitrate.
Aqueous Reactions: Cobalt(II) Chloride   
(Movie/Animation, Audio/Visual (13))
Reactions of solutions with aqueous Cobalt(II) Chloride.
Electrochemical Series: Metal Trees   
(Movie/Animation, Audio/Visual (11))
A piece of metal (Cu, Zn, Ag, Cd, or Pb) is placed in an aqueous solution of a metal ion (Cu2+, Zn2+, Ag+, Cd2+, or Pb2+). In some cases the growth of metal crystals indicates that a chemical reaction has occurred.
Ammonia (GCMP)   
(Interactive Simulation, Software (1))
Ammonia fountain: this is a resource in the collection "General Chemistry Multimedia Problems". In an ammonia fountain, a flask is filled with ammonia gas. A tube from the flask extends into a pan of water that contains phenolphthalein. When a rubber bulb full of water is squeezed, the water squirts into the flask. Water from the pan then is pushed into the flask and the indicator changes color. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.
Acids_and_Bases : BufferWeakWeak (14 Variations)   
(Assessment Material (1))
What mass of potassium bicarbonate (KHCO3) must be added to 500 mL of a 0.200 M carbonic acid solution to make a buffer with pH = 6.30?
Acids_and_Bases : CalcSolnpH (5 Variations)   
(Assessment Material (1))
Use this acid/base table to answer the question below.

Calculate the pH of a {x}M sodium acetate solution.

DO NOT use scientific notation
Enter your answer to two decimal places.
DO NOT enter units

Acids_and_Bases : BufferWeakStrong (7 Variations)   
(Assessment Material (1))
How many mL of a 2.50 M HCl solution must be added to 500 mL of a 0.150 M CO32- solution to make a buffer with pH = 10.00?
Acids_and_Bases : pHBufferCalc (4 Variations)   
(Assessment Material (1))
Calculate the pH of a buffer solution containing {x}M NH3 and {y}M NH4NO3.

Enter your answer to TWO decimal places.
DO NOT use scientific notation.
DO NOT enter units
        eg:     4.55

Acids_and_Bases : pHDilution (6 Variations)   
(Assessment Material (1))
What is the pH of a solution made by diluting {x} mL of {y} M HNO3(aq) to a total volume of 500 mL?

Enter your answer to two decimal places.
DO NOT use scientific notation

Acids_and_Bases : BufferingCapacity (20 Variations)   
(Assessment Material (1))
If a buffer is prepared using 0.75 mol CH3COOH and 0.45 mol CH3COO- in 1 liter of aqueous solution, is the buffering capacity of the solution great enough to maintain its pH if 10 g NaOH is added?
Acids_and_Bases : WeakAcidSolnpH (20 Variations)   
(Assessment Material (1))
Given an aqueous solution of 0.30 M acetic acid (Ka = 1.8 x 10-5), the pH is approximately ...
Acids_and_Bases : WaterAutoIonization (20 Variations)   
(Assessment Material (1))
What effect will the addition of H2CO3 have on the autoionization of water?

Acids_and_Bases : PracticalAcidBase (20 Variations)   
(Assessment Material (1))
Which of the following statements is true?
Acids_and_Bases : LewisAcidBaseRxns (19 Variations)   
(Assessment Material (1))
Identify the Lewis Acid and Base in the reaction of Ag+ and NH3 to form Ag(NH3)2+
Acids_and_Bases : TitrationCurveKaKb (8 Variations)   
(Assessment Material (1))
Study the graph of the titration of a weak acid with a strong base shown below. What is the approximate Ka for this acid?

Acids_and_Bases : PercentDissociationKa (3 Variations)   
(Assessment Material (1))
Calculate the percent dissociation in a {x}M aqueous solution of the weak acid HA. (Ka = {y} x 10-4)

Enter your answer to ONE decimal place.
DO NOT use scientic notation.
DO NOT write in the units.

Acids_and_Bases : AcidicOrBasicSalt (20 Variations)   
(Assessment Material (1))
When dissolved in an aqueous solution, which of the following salts will yield an acidic solution?
Acids_and_Bases : AcidBaseProperties (10 Variations)   
(Assessment Material (1))
Which of the following are properties of HCl?
AcidBaseProducts (10 variations)   
(Assessment Material (1))
The following acid/base table may be useful in answering the question below.

What products will result when HSO4- is added to water? Complete and balance the reaction below.

HSO4- + H2O ?

Acids_and_Bases : ProtonTransferRxn (20 Variations)   
(Assessment Material (1))
Write an equation to describe the proton transfer that occurs when the following acid is added to water: HSO4-
Enter the products in the space below using the following as an example:
What ions are present in an aqueous calcium nitrate solution?
Ca(NO3)2(aq) Ca2+(aq) + 2NO3-(aq)
In this case, the answer would be: Ca2+(aq) + 2NO3-(aq)
You should enter: Ca^(2+) + 2NO3^(-)
In other words, use the ^ to indicate superscripts; put charges in parentheses; and leave a space on either side of the + sign. Your answer must be an exact match for the computer to grade it correctly, so be careful.

What products will result when HSO4- is added to water?

Reactions : IDSampleRxnVideo (7 Variations)   
(Assessment Material (1))
You have an unknown aqueous sample. You add aqueous copper(II) sulfate to the sample. View the video below and determine which of the compounds listed below could be your sample.

Acids_and_Bases : SolnGrams (20 Variations)   
(Assessment Material (1))
How many grams of sodium hydroxide (NaOH) must be dissolved in 510 ml of water to make a solution with a pH = 8.1?
Acids_and_Bases : ChooseIndicator (8 Variations)   
(Assessment Material (1))

A 25.0 mL aliquot of a 1.44M solution of ammonia (Kb = 1.8 x 10-5) is titrated with 1.50M HCl. Use the Indicator Table below to decide which of the indicators listed would most accurately signal the equivalence point for this titration.

Write the letter corresponding to your choice of indicator in the box.

Acids_and_Bases : WeakStrongAcidPics (11 Variations)   
(Assessment Material (1))
Which diagram best represents an aqueous solution of HCl? (Water is not shown.)

Acids_and_Bases : ReactProductFavored (20 Variations)   
(Assessment Material (1))
You may want to use the following acid/base table to answer the question below.

Which of the following reactions will be product -favored?

Acids_and_Bases : IDLewisAcidBase (20 Variations)   
(Assessment Material (1))
Which of the following is a Lewis acid?
Acids_and_Bases : HendersonHassel (20 Variations)   
(Assessment Material (1))
You may want to use the following acid/base table to answer the question below.

Papain is a thiol protease isolated from papaya. The optimal pH for its enzymatic activity is 6.0-7.0. Which of the following buffering systems would work best for a laboratory experiment requiring active papain at pH 6.5? What molar ratios of the compounds would you use to prepare the solution?

Acids_and_Bases : ConjugateAcidBase (20 Variations)   
(Assessment Material (1))
Identify the acid and base that are reactants and the conjugate acid and conjugate base that are products in the following equation:
HI(aq) + H2O(l)  H3O+(aq) + I-(aq)
Acids_and_Bases : MolcScaleAcidBase (10 Variations)   
(Assessment Material (1))
Study the four drawings below and then decide which best represents an aqueous solution that has

(Water molecules are not shown in the diagrams.)

Acids_and_Bases : IonizationSteps (20 Variations)   
(Assessment Material (1))
Citric acid (which is a triprotic acid) has the following structure:

Which of the following equations corresponds to the first ionization step of the acid?
Reactions : ExchangeRxn (10 Variations)   
(Assessment Material (1))
Which of the following compounds would result in an exchange reaction if mixed in an aqueous solution with Ba(OH)2?
Reactions : Solubility (8 Variations)   
(Assessment Material (1))
Which of the following compounds are soluble in water?
Reactions : BalanceIonEquation (10 Variations)   
(Assessment Material (1))
What is the balanced net ionic equation for the following reaction:

AgNO3(aq) + HCl(aq) AgCl (s) + HNO3(aq)

Reactions : WillSolnConduct (5 Variations)   
(Assessment Material (1))
One gram of each of the following compounds is mixed with 100mL of water. Which will form solutions that will conduct electricity?
Reactions : PredictRxnProducts (5 Variations)   
(Assessment Material (1))
What are the most likely products from the reaction of aqueous sulfuric acid and aqueous sodium hydroxide?
Molecular Models of EDTA and Other Chelating Agents   
(Article (1))
Deirdre Bell-Oudry presents a variation on an old theme in her paper on using an indirect EDTA titration for sulfate analysis (1). EDTA and (often loosely) related species are this month's Featured Molecules.EDTA is a hexaprotic acid (H6Y2+) having the pKa values given in the featured paper (1). Figure 1 shows a distribution diagram for the EDTA system (2). At the pH of normal waters, the predominant species have one or both of the nitrogen atoms protonated.Complexation, however, requires that both nitrogens be deprotonated and it is generally assumed that the form that complexes with metal ions is Y4−. Structures of several forms of EDTA are included in the molecule collection (Figure 2). These structures are quite flexible having many conformations that are readily accessible at room temperature.An introduction to EDTA chemistry leads to broader questions of metal ion chelation or sequestration. Related chelating agents included in the molecule collection are EGTA, DCTA, NTA, BAPTA, and DTPA. Molecular dynamics and Hartree-Fock calculations on BAPTA (Figure 2) confirm that many conformations, ranging from those with the phenyl rings parallel to one another, to more elongated forms, are essentially isoenergetic in room temperature aqueous solution (3).Also included in the molecule collection are several crown ethers, an isophore (nonactin), and a cryptand. These not only provide students with a glimpse of the types of molecules being employed for metal ion sequestration but open a wide range of topics of current research in a variety of areas of inorganic, industrial, environmental, and biological chemistry.
Ionic Equilibria in Aqueous Solutions in Foods   
()
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
The Nobel Prize and Aqua Regia   
()
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.