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Lana L.'s Resources

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ANSWER AND DISCUSSION PROBLEM #1, SET 3 - NUMBERS and MATH 1. How many ounces is 45.0 tonnes? This problem is clearly a DA - only problem because it asks you to convert from metric tonnes to English ounces. Here is a list of the definitions to use: 1 tonne = E3 kg 1 kg = E3 g 1 # = 453.6 g (the metric - to - English "bridge") OR 1kg = 2.2 # (This... read more

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ANSWER AND DISCUSSION PROBLEM #1, STATES OF MATTER 1. How much heat is needed to warm 25 grams of water from 10.ºC to 20.ºC? (The decimals after the 10 and 20 have just been placed there to indicate that the numbers are accurate to two significant digits.) See the graph below for a picture of what is happening in these problems. Heat is added and the temperature of the water... read more

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How to do these STP gas and mass stoichiometry problems in general. All of the problems in this set are stoichiometry problems with at least one equation participant as a gas at STP. (a) Write and balance the chemical equation. (2) Do the math in DA style using 1 mole gas at STP = 22.4 liters as a factor. In the following problems ALL GASES ARE AT STP. In this set of problems for the... read more

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ANSWER AND DISCUSSION PROBLEM #1, SET 1 - MOLS 1. How many pennies are in a mole of pennies? How many thousand-dollar bills (k-notes!) is that mole of pennies equal to in money value? The first part of the problem is easy based on the definiton that a mol of ANYTHING is 6.022 E23 of them. A mol of pennies is 6.022 E23 pennies. This is what is GIVEN in the second part of the question... read more

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Use of Graphing Calculator for pH Box Math [H+] = 2.75 E-6 Start with [H+] = 2.75 E-6. Input (-) (This is the 'change sign' button.), log (not ln, the natural log) 2 . 7 5 E (-) 6 and enter. The pH will be displayed as 5.560667306. It is dreadfully unrealistic to consider that number as a final answer of the pH of the solution because pH is not generally accurately measurable... read more

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The Words of Chemistry There is some truth to the idea that chemistry is a different language. Chemists use words with special scientific meanings and special scientific pronunciations. Ask a scientist to read the words "unionized" or "periodic." A non-chemist will say the first word as if it meant that a working place had a union. A chemist would say the same work as... read more

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Sachertorte, or the Chocolate Cake That Ate Cincinnati The sachertorte is a rich cake that originated in the Hotel Sacher in Vienna, Austria in the late eighteenth century. It asks to be eaten with a generous dollop of REAL whipped cream on a thin slice of the cake and a cup of coffee. You may take the coffee with or without sugar, but the Viennese tradition is to lighten the coffee with... read more

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prefix symbol value value 'puter jargon usage origin / plausible alternative deca- da 101 101 [3], used to be "deka" (1790-1866) Gk. ten "deka" hecto- h 102 102 [3] Gk. hundred "hekaton" kilo- k 10001 103 note... read more

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ALLOTROPES The word allotrope just means different type or alternate type. A number of elements appear naturally in more than one form at room temperature. The allotropes are usually due to the crystal shape, or lack of crystal shape, or the attachments of more than one atom of an element. One of the easiest materials to see and play with in this respect is sulfur. Most pharmacies will... read more

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ANSWER AND DISCUSSION PROBLEM #1, SET 1 - NUMBERS 1. What is 1.50 mm in km? This problem is clearly a DA - only problem because it asks you to convert from one unit of distance to another, mm to km. Both of the units are metric units, so it needs a metric definiton. Either use the common definitions of kilometer to meter and meter to millimeter or use the metric staircase. Notice... read more

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ANSWER AND DISCUSSION PROBLEM #1, SET 2 - NUMBERS 1. How deep would the water in a trench three inches wide and sixteen feet long have to be to contain 24.0 cubic feet of water? This problem is likely best done with W5P method because it asks for a length when you are given two other lengths and a volume. All units are in English system. GIVEN:   l1 = 16 ft.,  ... read more

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Explanation of Acid - Base Problems TITRATION AND pH PROBLEMS THE FOLLOWING SALTS IN WATER SOLUTION WILL HAVE A pH OF 7, -7(less than 7), +7(more than 7), OR INDETERMINATE (I). FOR EACH PREDICT THE pH OF THE SOLUTION. 1. Na2CO3 is a basic salt because NaOH is a strong base and H2CO3 is a weak acid. pH is above 7. 2. FeCl3 is an acid salt because Fe(OH)3 is weak base and HCl... read more

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Wild Ideas DON'T EVEN THINK OF READING THIS IF YOU HAVE INCLINATIONS TOWARD CEREBRAL OSSIFICATION Big Bang or Big Bust? What is the Big Bang? The Big Bang Theory is that there was a time when all matter in the universe was initiated from an infinitely dense point that initially expanded at a rate that dwarfed the square of the velocity of light. The main body of evidence for this comes... read more

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Acids and Bases What Is An Acid Or A Base? By the 1884 definition of Svante Arrhenius (Sweden), an acid is a material that can release a proton or hydrogen ion (H +). Hydrogen chloride in water solution ionizes and becomes hydrogen ions and chloride ions. If that is the case, a base, or alkali, is a material that can donate a hydroxide ion (OH-). Sodium hydroxide in water solution... read more

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Solutions Properties of Solutions A solution is a mixture of materials, one of which is usually a fluid. A fluid is a material that flows, such as a liquid or a gas. The fluid of a solution is usually the solvent. The material other than the solvent is the solute. We say that we dissolve the solute into the solvent. Some solutions are so common to us that we give them a unique... read more

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Redox and Electroplating How Are Redox Reactions Different? Redox is the term used to label reactions in which the acceptance of an electron (reduction) by a material is matched with the donation of an electron (oxidation). A large number of the reactions already mentioned in the Reactions chapter are redox reactions. Synthesis reactions are also redox reactions if there is an exchange... read more

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Balancing Burning Equations Most burning reactions are the oxidation of a fuel material with oxygen gas. Complete burning produces carbon dioxide from all the carbon in the fuel, water from the hydrogen in the fuel, and sulfur dioxide from any sulfur in the fuel. Methane burns in air to make carbon dioxide and water. _ CH4 + _ O2 ===> _ H2O + _ CO2 Easy. Put a two in front... read more

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Reactions What is a chemical reaction? A chemical reaction is material changing from a beginning mass to a resulting substance. The hallmark of a chemical reaction is that new material or materials are made, along with the disappearance of the mass that changed to make the new. This does not mean that new elements have been made. In order to make new elements, the nuclear contents must... read more

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Compounds Ionic and Covalent Bonds A bond is an attachment among atoms. Atoms may be held together for any of several reasons, but all bonds have to do with the electrons, particularly the outside electrons, of atoms. There are bonds that occur due to sharing electrons. There are bonds that occur due to a full electrical charge difference attraction. There are bonds that come about from... read more

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Numbers and Math Operations Measured vs. Exact Numbers Exact numbers are numbers that are exact by definition, such as: 1 inch = 2.54 cm or 1 gallon = 231 cubic inches or 1 foot = 12 inches or 1 meter = 100 centimeters or numbers that come in integers and are not likely to be available in amounts smaller than integers. (When you ask for seating in a restaurant, the number of... read more

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