Solutions

Free Articles

Salting Roads: The Solution for Winter Driving
February 2006 (pp 14-16)

Author:  Doris Kimbrough
Chemistry Connections:
  Bonding, Solids/Liquids/Gases, Solutions, Thermochemistry
Description:
  Discusses freezing point depression and ions, compares salt to other de-icers in terms of number of particles formed when they dissolve. Also shows phase diagram for salt-water mixture. Describes new technology that also addresses highway safety in wintry conditions.

Paintball:  Chemistry Hits Its Mark
April 2007 (pp 4-7)

Author:  Brian Rohrig
Chemistry Connections: 
Solutions, Bonding. Solids, Liquids and Gases
Description: 
Describes the three major components of a paintball system—the gels that comprise the paintball shell, the liquid paint inside and the carbon dioxide propellant.  Explains water solubility issues with paint, which is composed of polyethylene glycol, and shell. Emphasizes hydrogen bonding and the polarity of molecules. CO2 propellant explanation relies on pressure and vapor pressure equilibrium.

Letting Off Steam
April 2009 (pp 4-7)

Author:  Carolyn Ruth
Chemistry Connections: 
Reactions, Solutions, Equilibrium, Solids/Liquids/Gases
Description:
  Information on the mechanics of geyser and hot spring formations that include deep earth heating of water which dissolves various molten rock (magma) minerals (silicon dioxide, calcium carbonate) that is brought to the surface to form solidified deposits. Other chemicals in an eruption include mercury, arsenic, hydrogen sulfide and carbon dioxide. Last page includes two student activities: making a volcano with soap, baking soda and vinegar, and boiling water at various temperatures with a vacuum filtration flask and a faucet with a suction filtration attachment.

Articles available on the ChemMatters DVD


The Quest for a Clean Drink
April 2008 (pp 4–6)

Author: Christen Brownlee
Chemistry Connections:
Bonding, Metals/Nonmetals, Reactions, Solutions, Sustainability
Description:
Tells of the problems in India and Bangladesh of obtaining clean drinking water, starting with contamination of surface water, followed by arsenic contamination of groundwater. Then discusses three different practical methods of purifying the water to remove the arsenic, all of which are being used successfully in these countries. The chemistry, including equations of the processes is illustrated.

Ancient Soil Chemists of the Amazon
February 2009 (pp 7–9)

Author: Mark Michalovic
Chemistry Connections:
Reactions, Solutions, Sustainability
Description:
Unraveling an ancient mystery as to how rainforest soils could be used for cultivation by Amazonians 500 years ago. Natives altered the soil with charcoal (biochar) to create negatively charged particles (carboxylates) that attract important nutritional positive ions (calcium, potassium) that plants need. Normal rainforest soil high in positively charged clay particles from aluminum and iron that do not attract needed calcium and potassium.

Bringing Chemistry to the Kitchen
February 2009 pp (10–12)

Author: Patrice Pages
Chemistry Connections:
Organic/Biochemistry, Reactions, Solids/Liquids/Gases, Solutions
Description:
Experimental cooking based on some understanding of chemistry and physics but primarily experimental using new physical forms of ingredients in the mix. Influence of color on taste perception studied; good taste influences amount eaten (savoring means less eaten)

The Forensics of Blood
February 2008 (pp 4–7)

Author: Brian Rohrig
Chemistry Connections:
Organic/Biochemistry, Solutions
Description:
Describes how chemists determine if a substance at a crime scene is blood (luminol and hydrogen peroxide or phenolphthalein and hydrogen peroxide), and if so, if it is human blood (rabbit antibody clotting test). Discusses blood as a colloid. Also tells how criminal investigators can determine blood type. Discusses useful information about blood stains – shape of blood droplets, transfer stains, projected stains. Two sidebars discuss the composition of blood, and the role of antibodies and antigens in determining blood type. The equation describing the reaction of luminol with hemoglobin is shown.

ChemHistory: The Race for Iodine
December 2006 (pp 18–19)

Author: Mark Michalovic
Chemistry Connections:
History/Biography, Periodicity, Reactions, Solutions
Description:
Relates the history behind two competitive chemical pioneers, Davy and Gay-Lussac, their simultaneous investigation to determine the chemical composition of a purple substance isolated from seaweed. Both chemists determine it is the element iodine, not a chlorine compound.

Glass: More Than Meets the Eye
October 2006 (pp 4–8)

Author: Brian Rohrig
Chemistry Connections:
Reactions, Solids/Liquids/Gases, Solutions
Description:
Details the physical and chemical tests used at crime scenes for analyzing glass. Includes density, chemical composition, chemical changes, and type of fracture. Two student activities are included: Disappearing glass with glycerol and water, and Forensic Identification of Glass, with isopropanol and water.

Flaking Away
February 2006 (pp 17–19)

Author: Christen Brownlee
Chemistry Connections:
Metals/Nonmetals, Reactions, Solutions, Sustainability
Description:
Talks about the demise of older cars due to rusting, focusing on the role of electrons in this chemical reaction, oxidation-reduction. Discusses how different regions of the same metal piece can act as anodes and cathodes simultaneously, and how water as a solvent for ions on the surface is the connector between these two areas of positive and negative charge that allows redox to occur. Differences in rusting rates in different geographical regions of the country are attributed to the presence of salt, either from ocean spray in coastal areas, or from salting of roads in colder regions of the country. Also discussed: reversing the rusting process (not practical), other objects that rust, the cost of rust, and paints to prevent corrosion. Chemical equations for rusting are provided.

Kitty Litter Chem
October 2005 (pp 12–14)

Author: Amanda Yarnell
Chemistry Connections:
Acids/Bases, Bonding, Solids/Liquids/Gases, Solutions
Description:
Discusses the relatively short history of cat litter (<60 years) and the four main types of cat litter—Fuller’s earth, bentonite (Montmorillonite), silica gels and plant-derived materials like Swheat Scoop. Talks about the chemistry of each type, including odor control (by protonation of NH3 to NH4+, absorbents, fragrances and antibacterial agents) and clumping of clays (absorption of water between layers of clay, causing swelling of the clay). Molecular models of Montmorillonite before and after the addition of water are shown.

The Great Hartford Circus Fire
February 2005 (pp 4–7)

Author: Brendan Rimetz
Chemistry Connections:
Bonding, History/Biography, Organic/Biochemistry, Reactions, Solutions
Description:
Tells the history of a fire that destroyed the Ringling Brothers and Barnum & Bailey Circus “big top” tent in July, 1944 and killed or injured almost 900 people. Focuses on waterproofing agent, composed of paraffin wax and gasoline. Discusses polarity of water, and non-polarity of gasoline and paraffin, and why the latter two chemicals were used to waterproof the tent canvas, and describes the synergistic (in this case, synergistically BAD) effects of using the two organic substances together, and why firefighters using water to put out the fire were unsuccessful. Discusses second waterproofing substance, with little known about its composition. Sidebar tells a survivor’s story. Second sidebar discusses colloidal dispersions to dissolve polar and non-polar substances together.

Lab on a Stick
October 2004 (pp 9–12)

Author: Christen Brownlee
Chemistry Connections:
Acids/Bases, History/Biography, Organic/Biochemistry, Reactions, Solutions
Description:
Recounts attempts to find an easy-to-use colorimetric urine test for diabetes. Includes early chemical testing, from the use of copper (II) sulfate-sodium hydroxide-ammonia reagent, to the advance made by Walter Compton who combined the reagents into tablet form (called Clinitest), to the modification made by Helen and Al Free which was a tablet that tested urine for ketone bodies. Describes the paper strip test, also developed by the Frees, which uses glucose enzymes to test for sugar in urine. Eventually the paper strip developed by the Frees contained ten tests in a single strip. The test strips are called Multistix-10SG. Article includes photos of the test strips. An interview with Helen Free follows the article.

ChemHistory: Cleopatra's Perfume Factory and Day Spa
October 2004 (pp 13–15)

Author: Lois Fruen
Chemistry Connections:
Reactions, Solids/Liquids/Gases, Solutions
Description:
Describes Cleopatra’s contributions to skin care treatments, which she developed at the spa and perfume factory given to her by Mark Anthony. The article notes the chemicals that were used in these ancient treatments and describes how modern chemistry has confirmed their composition by modern analysis. A sampling of ancient substances includes tar or pitch, salt, moringa oil, horseradish oil, olive oil and henna. The article lists modern chemicals that were present in some of Cleo’s formulations—indoles, amines, copper (II) carbonate, lead (II) sulfide and lead carbonate. The latter two compounds do not occur naturally, and the article describes the way in which the Egyptians synthesized them.

Green Chemistry: Building a Better Bleach: A Green Chemistry Challenge
April 2004 (pp 17–19)

Author: Kathryn Parent
Chemistry Connections:
Solutions, Sustainability
Description:
Describes the chemistry of chlorine bleaching with special emphasis on how the use of chlorine bleach can result in chlorine being converted to chlorine compounds like dioxins. Explains that the active ingredient in non-chlorine bleach is a hydrogen peroxide d rather than the hypochlorites in chlorine bleach. Suggests that non-chlorine bleaches are more environmentally friendly but have drawbacks of their own—they require higher temperatures and pressures to be effective. Describes the development of catalysts called tetra-amido macrocyclic ligands (TAML), which allow non-chlorine bleaches to work well at lower temperatures and pressures.