This molecular orbital model can be used to explain why He2 molecules don’t exist. Combining a pair of helium atoms with 1s2 electron configurations would produce a molecule with a pair of electrons in both the bonding and the * antibonding molecular orbitals. The total energy of an He2 molecule would be essentially the same as the energy of a pair of isolated helium atoms‚ and there would be nothing to hold the helium atoms together to form a molecule. The fact that an He2 molecule is neither
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Chemistry I Chapter 8 Review Problems Part I Using the factor label method‚ neatly and clearly show all work. Answers are to include the unit‚ be in correct number of significant figures. If the answers are less than 1.0 or greater than 10‚ they are to be written in and be in correct scientific notation. Box your final answer. Mass/Mole Problems 1. Determine the molar masses of the following compounds: a. dinitrogen pentoxide c. sodium carbonate b. ammonium
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~ Graded Assignment I) Name: . 1\ \ \ ~o ni-! SC1303A/304A: Chemistry 1Unit 41 Lesson 17: Unit Test I .’ / j ! Graded Assignment Unit Test‚ Part 2 Answer the questions below. You may use the periodic table in the Chemistry: Problems and Solutions book for this test. When you have finished. submit this assignment to your teacher by the due date for full credit. (5 points) 1. You have three elements. A. B. and C. with the following electronegativity values: A = 0.9 B =3.0 C = 3.5 You
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1. Atomic masses are expressed on a scale based on the mass of what? Carbon-12 2. Name the unit used to express atomic masses of individual atoms. Grams or molar mass‚ gmm 3. Define formula mass. Sum of the atomic masses of all atoms in a compound 4. What do we call the number of atoms of an element equal to the number of atoms in exactly 12.0 grams of carbon-12? Mole or Avogadro’s number 5. How many atoms are in a sample of an element whose mass is numerically equal to the atomic
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Identification of a Copper Compound by Percent Mass Unknown Compound: #9 Abstract: The objective of this experiment was to identify the unknown pure copper salt compound of #9. To do this‚ the mass of copper in the unknown was calculated and then divided by the mass of the whole compound to get the percent copper. The molecular weight was also calculated by dividing mass of copper compound used by moles of compound in unknown sample. The percent copper averaged out to 31.6% while the molecular
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Preparation of Calcium Carbonate Lab In this laboratory activity you will attempt to produce 1.00g of calcium carbonate from aqueous solutions of calcium chloride and sodium carbonate. These solutions will be prepared from 2.01 g of calcium chloride and 1.06 g of sodium carbonate . Materials: 3 beakers 100 mL graduated cylinder rubber policeman funnel filter paper Procedure: 1. Put on your safety goggles. 2. Obtain two clean beakers. Rinse the inside of the beakers with a small
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Separating a Mixture of Compounds Exp. No. 2 name Chemistry 145 February 2‚ 2014 I. Purpose The purpose of this experiment was to separate this mixture into components‚ determine the mass and percentage of each component. In addition to test the accuracy of an alternative method of subtraction to find the mass of the sodium chloride directly. Start with a mixture of sand (SiO2)‚ sodium chloride (NaCl)‚ and ammonium chloride (NH4Cl)‚ and use these separation processes: sublimation filtration
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Introduction: Copper (II) Chloride is the compound with a chemical formula of CuCl2. This is a light brown solid‚ which slowly absorbs moisture to form a blue green dihydrate. Copper (II) Chloride is highly soluble in water and will produce a blue solution. solutioAluminum is the compound that has a chemical formula of Al. This is a silver solid that can be easily formed‚ machined‚ or cast. In this lab‚ we will be finding the limiting reactant between Copper(II) Chloride and Aluminum. The limiting
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In order to find the formula of the copper chloride hydrate‚ we had to separate the compound to find the mass of water and copper. To begin this process‚ we evaporated the water and created an anhydrous compound‚ meaning we were left with only CuxCly. By calculating the weight of both the anhydrous and the hydrated compounds‚ we could conclude that the difference in the weights was the weight of the H2O. From this we were able to calculate the percent composition of CuxCly and H2O (see Calculations:
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Copyright © Glencoe/McGraw-Hill‚ a division of the McGraw-Hill Companies‚ Inc. Formula Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 N2H4 H N N H H H 14 7 H N N H H H H N H 2 N H H Unnecessary (octets complete) SiO2 O Si O O Si O Name Date Class TEACHING TRANSPARENCY WORKSHEET Lewis Structures 29 Use with Chapter 8‚ Section 8.3 1. Step 1 in drawing the Lewis structure for a molecule is to decide which atoms of the molecule
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