Thursday, October 24, 2019

Gas Laws Lab Essay

Introduction: The four basic physical properties of a gas sample are pressure, volume, temperature, and number of moles. The volume simply indicates the volume of the container since a gas will take up all space available to it. The temperature indicates the average kinetic energy of the gas particles. For gases, the temperature must be converted to the Kelvin unit. The pressure of the gas indicates the number of collisions with each other and the wall of the container. The number of moles indicates the amount of gas particles. Gases do not have a definite shape of volume. Gases spread out into their container and occupy the entire volume available, which means they are free to move around and have large amounts of empty space. In many chemical reactions, gases are produced; for example, reactions involving metal carbonates that react with an acid produce gaseous carbon dioxide. Objective: To determine the volume of gas produced from a reaction between a metal carbonate and acid and to determine the identity of an unknown carbonate salt. Pre-Lab Questions: 1. If you increase the temperature what happens to the speed of the particles? Explain. 2. What is the formula to convert Celsius temperature to Kelvin? a. Â °C+273.15=K 3. What are the standard conditions for a gas? Are you at standard conditions in the lab? 4. Boyle’s Law – The principle that the volume of a given mass of an ideal gas is inversely proportional to its pressure, as long as temperature remains constant. Boyle’s law is a subcase of the ideal gas law. P1V1 = P2V2 Charles’ Law – The law of volumes. The volume of a fixed amount of gas at constant pressure is directly proportional to the Kelvin temperature of the gas. (Temperature must be in Kelvin). V1T1= V2T2 V/T = K V1T2 = V2T1 Gay-Lussac’s Law – Pressure is directly proportional to temperature if the volume is constant. P1/T1 = P2/T2 5. What is the Ideal Gas Law in formula form? What is the value for the proportionality constant with units? Why are those units so important? b. PV = nRT c. C = PV / T 6. Write the balanced equations for CaCO3, BaCO3, Li2CO3, and Na2CO3 reactions with hydrochloric acid. 7. Calculate the molar mass of these same four metallic carbonates. LiCo3 = mass/mole; 3.0036g/0.0344 mol = 87.31 g/mol Materials/Equipment: * 3.0 M HCl (aq) * 5 ml graduated cylinder * Balloon String * Scissors * Weighing paper * 3g of unknown #2 carbonate salt * Funnel Procedures: First measure out 5ml of 3.0 M HCl into the graduated cylinder and weigh 3 g of the unknown carbonate salt. Using the funnel, pour the unknown carbonate salt into the balloon and put the open end of the balloon over the graduated cylinder and secure with a string. It is important to make sure the string is very tight to prevent the gas from leaking. Empty the contents of the balloon into the graduated cylinder that contains the 3.0 M HCl. After the gas fills the balloon, use a string and measure the circumference of the balloon.| Observations:Carbonate is limiting reactant.| Conclusion: Based upon our experiment, equations, and calculations that our unknown Carbonate Salt for Unknown # D was Li2CO3 – Lithium Carbonate. There could be a number of factors that could have caused us to receive an 18.1% error. How we held the balloon when tipping it over the acid could greatly affect the radius of our balloon.

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