Higher Level Worksheets. The chemical industry. Introduction The chemical industry creates an immense variety of products which impinge on virtually every aspect of our lives. Figure 1 The chemical industry is one of the largest manufacturing industries in all developed and emerging countries. This is a view of the largest site in the world devoted to the industry, at Ludwigshaven in Germany. By kind permission of BASF.
While many of the products from the industry, such as detergents, soaps and perfumes, are purchased directly by the consumer, 70% of chemicals manufactured are used to make products by other industries including other branches of the chemical industry itself. With increasing competition worldwide, innovation remains crucial in finding new ways for the industry to satisfy its increasingly sophisticated, demanding and environmentally-conscious consumers. What does the chemical industry produce? The products of the chemical industry can be divided into three categories: Basic chemicalsSpeciality chemicalsConsumer chemicals. Titration Calculations.
Before you go any further, check that you can do the following… Calculate: Relative molecular masses from a given chemical formula Calculate: Number of Moles from the mass/RMM equation Manipulate: The number of moles equation to get the form you require. When you are confronted by a Titration calculation the first rule is: The Second rule is read through the question very carefully.
The Third rule is read through the question carefully again! We are now going to look at a question and hopefully guide the unbelievers (henceforth known as infidels) through a titration calculation. The question: 10.0 cm3 of a solution of potassium hydroxide was titrated with a 0.10 M solution of hydrochloric acid. 13.5 cm3 of the acid was required for neutralization.
Step 1 Write down everything you know. Hydrochloric Acid Potassium hydroxide Volume used = 13.5 cm3 Volume used = 10.0 cm3 Concentration = 0.10 M Concentration = TBD Step 2 Write the equation or as much as you know about it. Step 3 Step 4 Questions 1. 2. King of random. Mrs. J's Chemistry Page - Lecture Notes. Printable Chemistry Worksheets - Free pdf Worksheets to Download or Print. This is a downloadable soft colored periodic table of the elements which shows atomic number, element symbol, element name and atomic mass. Todd Helmenstine This is a collection of chemistry worksheets in pdf format. The answers to the questions are available on separate worksheets so you can fill them out and then check your work. Please feel free to download these to your computer, print them, and use them as hand-outs. Printable Periodic Tables Here are some printable periodic tables to help you out, also in pdf format.
Printable Scientific Method Flow Chart This is a flow chart of the steps of the scientific method, available as a jpg, png, or pdf file: Also available is a PDF of a pie chart of the elemental composition of the human body. Adobe Acrobat Reader is needed to open and read pdf files (free download). Stay up to date on the latest chemistry news, learn chemistry, and get instructions for chemistry projects. Free stuff for teachers!
Creative Chemistry A Level Practical Work. Steam-distillation. ScienceList of Resources. Forensic Analysis: Laboratory and Pre-laboratory Manual- Learn Chemistry. Higher Education Resources. Main Page - Learn Chemistry Wiki. Egg in a Bottle Demonstration. The egg in a bottle demonstration is an easy chemistry or physics demonstration you can do at home or in the lab. You set an egg on top of a bottle (as pictured). You change the temperature of the air inside the container either by dropping a piece of burning paper into the bottle or by directly heating/cooling the bottle. Air pushes the egg into the bottle. Egg in a Bottle Materials peeled hard-boiled egg (or soft-boiled, if a yolk mess interests you) flask or jar with opening slightly smaller than the diameter of the egg paper/lighter or very hot water or very cold liquid In a chemistry lab, this demonstration is most commonly performed using a 250-ml flask and a medium or large egg.
Perform the Demonstration Method 1: Set a piece of paper on fire and drop it into the bottle. If you just set the egg on the bottle, its diameter is too large for it to slip inside. When you change the temperature of the air inside the bottle, you change the pressure of the air inside the bottle. Supercooling Water - How to Supercool Water. Nucleation. When sugar is supersaturated in water nucleation will occur, allowing sugar molecules to stick together and form large crystal structures.
Nucleation is the process of forming a nucleus. It is the initial process in crystallization. Nucleation is the extremely localized budding of a distinct thermodynamic phase. It is the process in which ions, atoms, or molecules arrange themselves in a pattern characteristic of a crystalline solid, forming a site in which additional particles deposit as the crystal grows. Some examples of phases that may form by way of nucleation in liquids are gaseous bubbles, crystals, or glassy regions.
Creation of liquid droplets in saturated vapor is also characterized by nucleation (see Cloud condensation nuclei). Nucleation of crystalline, amorphous, and even vacancy clusters solid materials is also important, for example to the semiconductor industry. A good example is the famous Diet Coke and Mentos eruption. Examples of nucleation[edit] where The term provides. Communicating chemistry: www treasure hunt- Learn Chemistry. Oil strike- Learn Chemistry.
How to Assign Oxidation Numbers Video. Through examples such as Iron, Sulfur, and Copper, in this video, learn how oxidation numbers relates to an electron's gain or loss.See Transcript Today I will discuss what oxidation numbers are and how they are assigned. Iron and Sulfur: Pure Elements Pure elements like iron and sulfur are electrically neutral because they have equal numbers of positive protons and negative electrons. When elements form compounds, electrons are often transferred from one atom to another and ions form. When iron burns with sulfur, as in fireworks, the iron atoms lose 2 electrons each and the sulfur atoms gain two electrons each. Metal Oxidation Numbers Since iron has lost 2 negative electrons, the ion has two more protons than electrons and has a net charge of +2. Copper Oxidation Numbers Copper can lose 1 or two electrons, resulting in oxidation numbers of +1 or +2. When carbon burns with oxygen, as in a barbecue with charcoal briquettes, carbon monoxide can form.
Kjeldahl method. The Kjeldahl method or Kjeldahl digestion (Danish pronunciation: [ˈkʰɛld̥æːˀl]) in analytical chemistry is a method for the quantitative determination of nitrogen in chemical substances developed by Johan Kjeldahl in 1883.[1] Method[edit] The method consists of heating a substance with sulfuric acid, which decomposes the organic substance by oxidation to liberate the reduced nitrogen as ammonium sulfate.
In this step potassium sulfate is added to increase the boiling point of the medium (from 337°C to 373°C) . Chemical decomposition of the sample is complete when the initially very dark-colored medium has become clear and colorless. The solution is then distilled with a small quantity of sodium hydroxide, which converts the ammonium salt to ammonia. Degradation: Sample + H2SO4 → (NH4)2SO4(aq) + CO2(g) + SO2(g) + H2O(g) Liberation of ammonia: (NH4)2SO4(aq) + 2NaOH → Na2SO4(aq) + 2H2O(l) + 2NH3(g) Capture of ammonia: B(OH)3 + H2O + NH3 → NH4+ + B(OH)4– Applications[edit] Sensitivity[edit] Chromatography.
Pictured is a sophisticated gas chromatography system. This instrument records concentrations of acrylonitrile in the air at various points throughout the chemical laboratory. Automated fraction collector and sampler for chromatographic techniques Chromatography (/ˌkroʊməˈtɒɡrəfi/; from Greek χρῶμα chroma "color" and γράφειν graphein "to write"[1]) is the collective term for a set of laboratory techniques for the separation of mixtures. The mixture is dissolved in a fluid called the mobile phase, which carries it through a structure holding another material called the stationary phase. The various constituents of the mixture travel at different speeds, causing them to separate. The separation is based on differential partitioning between the mobile and stationary phases.
Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus changing the separation. Chromatography may be preparative or analytical. History[edit]