Chemistry 121 Experiment 19 Molar Mass Determination y Depression of the Freezing Point Introduction: The most commonly used liquid is water. In this experiment we study the equilibria that can exist between pure water and an aqueous solution‚ and ice‚ the solid form of water. The heat will transfer from a higher temperature to a lower temperature. In order for water to change states of matter‚ it takes a certain amount of kinetic energy or heat. The shift from ice to water (solid to a liquid)
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Molar pregnancy is an abnormal form of pregnancy in which a non-viable fertilized egg implants in the uterus and converts a normal pregnancy into an abnormal one (which will fail to come to term). A molar pregnancy is a gestational trophoblastic disease[1] that grows into a mass in the uterus that has swollen chorionic villi. These villi grow in clusters that resemble grapes.[2] A molar pregnancy can develop when an egg that is missing its nucleus is fertilized and that may or may not contain fetal
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How is molar mass calculated and why is it useful? You have to multiply the atomic weight of each element by the number of atoms that it contains in a compound. Molar mass is useful because its used to change a measurement of mass to an amount of a substance such as the number of particles. 2.Define a mole in chemistry and give 3 examples equivalent units that are used in chemical calculations. A mole measures the amount of a substance. Three examples that are equivalent to a mole is molar mass‚
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Abstract Molar volume is the volume that one mole of gas occupies when temperature and pressure are kept constant. The molar volume of a gas can be determined through evaluating how much gas is given off when the number of moles of the substance is known. To find the volume of gas that will be used to calculate the molar volume‚ the process of water displacement can be used. Reference Citation Cesa‚ J. (2002). ChemTopic labs: Experiments and demonstrations in chemistry (vol. 9). Batavia
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Vapor Pressure and Enthalpy of Vaporization of Water 1/9/12 Emily Toy Lab Partner: Zack Ronnei Instructor: Ms. Olsen‚ AP Chemistry Purpose: The purpose of this lab is to find the vapor pressure of water at temperatures between 50oC and 80oC. Procedure: 1. Take a10 mL graduated cylinder and fill it with 7 mL of water. 2. Next fill a 1000 mL beaker ¾ full with water. 3. Cover the graduated cylinder by putting your finger on top and place the cylinder in the 1000 mL beaker. Make
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Thermochemistry: An Ice Calorimeter Determination of Reaction Enthalpy Shannon Wedepohl 9/17/13 Abstract: During this experiment‚ an ice calorimeter was used to measure the change in volume in milliliters of magnesium metal and 1.00 M of sulfuric acid. We found the experimental molar enthalpy of the reaction to be ∆H = -370 ± 1 kJ/mol at 0˚C. This compares with an expected value of -466.9 kJ/mol at 25 ˚C‚ a 20.75% difference. Introduction: Many chemical reactions truly only
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Determination of the Enthalpy for Decomposition of Hydrogen Peroxide Objective: To construct a coffee cup calorimeter‚ measure its calorimeter constant‚ and determine the enthalpy of decomposition and formation of hydrogen peroxide. Background: This experiment is a classic thermodynamics lab. In it‚ we attempt to measure the enthalpy (H) of a chemical reaction. The main obstacle is that this is a quantity that cannot be measured directly. It instead is observed as heat from one substance is transferred
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AS TRANSITION COURSE SUMMER 2012 PART 1: MEASURING AMOUNT OF SUBSTANCE MASS VOLUME MOLAR MASS AVOGADRO [pic] CONCENTRATION ATOM ION MOLECULE COURSE OUTLINE OCR Chemistry A Unit 1 – Autumn Term 2012 • Atoms and Electron Structure • Moles‚ Equations and Acids • Structure and Bonding • Redox‚ Group 2 and Group 7 Unit 1 Exam – January 2013 – 1 hour – 90 UMS – 30% of total Unit 2 – Spring Term 2013 • Basic Concepts
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Determining an enthalpy change of a displacement reaction Aim: To determine the enthalpy change for the displacement reaction between zinc powder and copper (II) sulphate solution. Zn (s) + Cu2+ (aq) → Cu2+ (s) + Zn2+ (aq) Theory: For the displacement reaction‚ an excess amount of zinc powder is added to the measured amount of aqueous copper (II) sulphate. The temperature change over a period of time has to be measured and thus‚ the enthalpy change for the reaction can be measured. The equation
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change during a neutralization reaction Introduction: When an alkali neutralizes an acid‚ a salt and water are formed. Aqueous hydrogen ions (H+(aq)) from the acid react with the hydroxide ions (OH-(aq)) from the alkali‚ forming water. For hydrochloric acid and sodium hydroxide: H+(aq) + Cl-(aq) + Na+(aq) + OH-(aq) → Na+(aq) + Cl-(aq) + H2O(l) Hydrochloric acid Hydrochloric acid Sodium Chloride Sodium Chloride Sodium Hydroxide Sodium Hydroxide Neutralization is an exothermic
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