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Final Answers
© 2000-2011 Gérard P. Michon, Ph.D.

Practical Chemistry

  • Basic glassware:  Flasks, funnels, tubes, bulbs, condensers, etc.
  • PTFE  =  Polytetrafluoroethylene  =  Teflon®.
  • Ground-glass joints:  Standard glass-to-glass conical joints have a 1:10 taper.
  • Titration.  Measuring the volume of a reactant of known concentration.
  • Chemistry set  from a bygone era  (if memory serves).
  • Waterlock:  1 g of  sodium polyacetate  can hold  825 mL  of water.
  • Negative-X:  Water ignites a mixture of zinc and  ammonium nitrate.
  • Nitrogen triiodide  Is an extremely unstable explosive when dry.
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Related articles on this site:

Related Links (Outside this Site)

NIST Chemistry WebBook  |  CAS Registry Numbers (CAS RN)
Caveman Chemistry  |  Chemical How Tos  |  United Nuclear  experiments.
General Chemistry Starting Points  (for students)   by  Steve Lower.
Chem Toddler  Republic of Serbia:  Ministry of Science and Technological Development.
Sciencemadness.org  by  Matthew Ernst.
Forum Topics: Hardware Store Chemicals

Legendary Introductory Books :

Videos :

MIT OpenCourseWare :  Basic Chemistry  by  Sylvia Ceyer  &  Catherine Drennan.
Edward Kent's Chemical Demonstrations  |  Alkali Metals in Water  by  Dnn87
Top 10 Amazing Chemistry Videos  by  Aaron Rowe  at  Wired Science.
Steve Spangler Science :   Giant Smoke Rings   |   Genie in a Bottle
 
The Periodic Table of Videos :   118 video clips produced by  Brady Haran,
featuring Martyn Poliakoff, Pete Licence, Stephen Liddle, Debbie Kays and Neil Barnes.
 
Making TCPO for a Glow Stick (revisited)  |  Test-Tube Thunderstorm  |  Heated Sulfur in Pure Oxygen
 
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International Year of Chemistry - 2011

Practical Chemistry
Beaker Beaker

Aspirator bottle (2011-07-10)   Basic Glassware
Handling liquids  (and gases).

  • Test tube.  Boiling tube  [ tube à essai ].
  • Stirring rod  [ agitateur ].
  • Conical flask  (Emil Ehrlenmeyer, 1861).
  • Boiling flask, Florence flask  [ ballon ].
  • Beaker  [ bécher ].
  • Crystallizer, crystallizing dish  [ cristallisoir ].
  • Petri dish  [ Boîte de Petri ].
  • Watch glass  [ Verre de montre ].
  • Measuring cylinder  [ éprouvette graduée ].
  • Volumetric flask  [ fiole jaugée ].
  • Buret  [ burette ].
  • Pipet  [ pipette ].
  • Thistle funnel, thistle tube.
  • Separatory funnel  [ ampoule à décanter ].
  • Dropping funnel  [ ampoule de coulée ].
  • Pressure-equalizing dropping funnel  [ ampoule à brome ].
  • Eudiometer  (Landriani, 1775).
  • Aspirator bottle  (bottom side-arm).
  • Bottle  [ flacon ].
  • Squeeze bottle  [ pissette ].
  • Filter flask, side-arm vacuum flask, Büchner flask, Kitasato flask.
  • Büchner funnel  (with Büchner ring and either filter paper or sintered/fritted glass).
  • Desiccator jar.
  • Water aspirator  [ trompe à eau ].
  • Retort [ Cornue ]  (Geber, c. AD 750).
  • Alembic, still  [ alambique ].
  • Liebig (straight) and Graham (coiled) condensers  [ réfrigérants ].
  • Kjeldahl bulb  (or "ball").

Wikipedia :   Laboratory glassware   |   Laboratory glassware
French :   Verrerie de chimie   |   Matériel de chimie  (Quizz about names of glassware in French)

(2011-07-12)   PTFE = polytetrafluoroethylene   (Teflon® )
(CF2 )n  was discovered accidentally by  Roy J. Plunkett  in 1938.

Come back later, we're still working on this one...

(2011-07-12)   Joints
Ground-glass joints, hose connections, etc.

Ground-glass conical joints

In the trade, the inner contact surface is known as the  grind.

All standard joints have a precise 1:10 taper.  Their sizes are specified by two numbers; the largest diameter of the grind  (in mm)  and the length of the grind  (in mm).  A mismatch in length is usually inconsequential.  A  slight  diameter discrepancy can also be tolerated.  The 10/30 long joint seems to be for thermometers only...

Sizes (diameter/length in mm) of Ground-Glass Conical Joints
Keck
Clip		 Size  Wall
Thickness		US
  (long)  		 DIN
  12249  		Other
  (short)  
   3.5-5.0 mm  100/60
   3.5 mm  85/55
   3.2 mm  71/51
   2.5-3.2 mm  60/46
   2.5-3.2 mm55/50 55/44
   2.3-2.5 mm50/50 50/42
brown  2.3-2.5 mm45/5045/40 
gold6 2.0-2.3 mm  40/38
orange5 2.0-2.3 mm34/4534/3534/28
red4 2.0 mm29/4229/3229/26
green3 1.8-2.0 mm24/4024/2924/25
blue2 1.8 mm19/3819/2619/22
yellow1 1.5-1.8 mm14/35, 14/2014/2314/19
violet  1.5-1.8 mm12/3212/21 
  turquoise   0   thermometer  10/30  
1.5 mm10/3010/19 
   1.5 mm7/257/16 
   0.8 mm5/205/13 

Keck clips  were patented in 1984 (US patent 4,442,572) by Hermann Keck.  They are available mostly for medium-sized glassware joints  (10 mm to 45 mm in diameter)  in the above Delrin® color coding.

Come back later, we're still working on this one...

Wikipedia :   Ground glass joint   |   Sciencemadness Forum
Scribd's e-book :   Interchangeable Ground-glass Joints, Stopcocks
Trade :   Eagle Laboratory Glass Company   |   Glasscraft   |   Witeg   |   Duran Group

Bottom of the meniscus in a buret
(2011-07-11)   Titration
Measuring volumes and concentrations.

Come back later, we're still working on this one...

Wikipedia :   Titration   |   Acid-base titration
Titration and titrimetric methods  by  Marcin Borkowski.

(2011-07-31)   Chemistry Set from a Bygone Era
The contents of the chemistry set I had as a child  (if memory serves).

  • Glass stirrer.
  • Round-bottom and flat-bottom boiling flasks.
  • Verres à pied  (no beakers).
  • One-hole and two-hole stoppers.
  • Thistle funnels and glass tubes.
  • Retort
  • Mortar and pestle.
  • Evaporating dishes.
  • Crucible.
  • Tripod and mettalic gaze.
  • Alcohol burner with wick.
  • Test tubes and wooden rack.
  • Plastic crystallizers  (one with built-in electrodes).
  • Wooden holder.
  • Earthenware gizmo  (pierced bowl with sideways indentation).
  • Litmus paper.

Two wooden racks with small quantitues of inorganic and organic chemicals in labeled glass tubes with plastic stoppers.

  • Iron filings.
  • Sulfur.
  • Zinc dust.
  • Potassium permanganate.
  • Sodium bisulfite.   NaHSO3
  • Copper sulfate.
  • Silver nitrate.
     
  • Glucose.
  • Saccharose.
  • Citric acid.
  • Tartaric acid.
  • Malic acid (?)
  • KOH
  • Lye.   NaOH

(2011-08-27)   Waterlock :  Extreme Water Retention
1 g of  sodium polyacrylate  can hold  825 mL  of water.

Come back later, we're still working on this one...

Wikipedia :   Sodium polyacrylate   |   Superabsorbent polymer
Videos :   Vanishing Water (The Trick)   &   Vanishing Water Revealed  by  Edward Kent

(2011-08-28)   Negative-X
A mixture that's ignited by water.

The main reaction is:

NH4NO3  +  Zn   ®   N2  +  ZnO  +  2 H2O

However, it is best ignited by the following reaction, catalyzed by  Cl-  ions:

NH4NO3   ®   N2O  +  2 H2O

That subsidiary reaction can be started with a drop of concentrated hydrochloric acid.  Alternately, pure water (or just moisture) will ignite a mixture that already contains a little bit of chlorine ions, in the form of ammonium chloride  (or sodium chloride).  Also, the acidity may remove the oxidation layer of zinc to make the metal available for the main event:

United Nuclear
Videos :   Chemical fire  (Ammonium nitrate and zinc, ignited with HCl)

(2011-09-06)   Nitrogen Triiodide
An explosive set off by the touch of a feather or by  alpha radiation.

Come back later, we're still working on this one...

Wikipedia :   Nitrogen triiodide 
Videos :   Nitrogen Triiodide Detonation   |  

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visits since August 12, 2011
(c) Copyright 2000-2011, Gerard P. Michon, Ph.D.