Report ex2

Pre Lab Questions: Experiment Experiment 2: Prelaboratory Assignment Experiment Procedure,Part A a What is the criterion for clean glassware? - The absence of any lingering substances that can potentially have an impact on the experiment's outcome qualifies as clean glassware They must be completely cleaned and disinfected b What is the size and volume of a “small, clean test tube”? - The size of a small, clean test tube is 75mm The volume of a small and cleantest tube is 3mL Exiperiment Procedure, Part A.2 Describe the technique for testing the odor of a chemical -The technique for testing the odor of a chemical is wafting To explain, you must place your hand above the test tube and in a circular motion, in the direction of your face, and nose, motion the movement and the wave of your hands to direct the air in the direction towards your face Identify at least five observations that are indicative of a chemical reaction - At least five observations that are indicative of a chemical reaction, are the gas evolves, theprecipitate appears or disappears, the heat is given off or absorbed, there is a noticeablechange in color and finally, there is a noticeable odor Experimetal Procedure, Part A.1 Referring to Appendix G for the substances listed here; underline those that are soluble and circle those that are insoluble: AgNO3: underline NaCl: underline AgCl: circle Na2CO3: underline Ag2CO3: circle MgSO4 :underline Ag2SO4: underline NH4CL: underline Experimental Procedure, Part A The substances NaCl, Na₂CO₃, CO₃, , MgSo , and NH Cl, which are used for test solutions, are all soluble ionic compounds For each substance, indicate the ions present in its respective test solution NaCl: Na⁺Cl⁻Cl⁻ Na₂CO₃, CO₃, : CO₃, ²⁻ MgSo :Mg²⁺Cl⁻SO ²⁻ NH Cl:NH ⁺Cl⁻Cl⁻ Three colorless solutions in test tubes, with no labels, are in a test tube rack on the laboratory bench Lying beside the test tubes are three labels: potassium iodide, KI; silver nitrate, AgNO₃, ; and sodium sulfide, Na₂CO₃, S You are to place the labels on the test tubes using only the three solutions present Here are your tests: A portion of test tube added to a portion of test tube produces a yellow A portion of test tube added to a portion of test tube produces a yellow silver iodide precipitate ● A portion of test tube added to a portion of test tube produces a black A portion of test tube added to a portion of test tube produces silver sulfide precipitate ● A portion of test tube added to a portion of test tube produces a yellowsilver iodide precipitate ● A portion of test tube added to a portion of test tube produces a black a Your conclusions are: Test tube 1:silver nitrate Test tube 2:sodium sulfide Test tube 3: potassium iodide b Write a balanced equation for the formation of silver iodide, AgI, from a mix of two selected solutions provided above X + Y → AgI AgNO₃, +KI→AgI+KNO₃, c Write the balanced equation for the formation of silver sulfide, Ag₂CO₃, S, from a mix of two selected solutions provided above X + Y→Ag₂CO₃, S AgNO₃, +NA₂CO₃, S→Ag₂CO₃, S+ NaNO₃, (unbalanced) 2AgNO₃, +NA₂CO₃, S→Ag₂CO₃, S+ 2NaNO₃, (balanced) Laboratory Questions Identify a chemical reagent used in this experiment that can be used to distinguish solid CaCl2 (soluble) from solid CaCO3 (insoluble) What is the distinguishing observation? - The chemical reagent used in this experiment that would distinguish CaCl2 (soluble) from CaCO3 (insoluble) would be Hal If HCl is added, then the compound CaCO3 (insoluble) will fix On the other hand, the compound CaCl2 (soluble) will not fix So the distinguishing observation would be fizzing which indicates the creation of a gas What test reagent used in this experiment will distinguish a soluble Cl- salt from a soluble SO42– salt? What is the distinguishing observation? - The test reagent that was used in this experiment that will distinguish a soluble Cl- salt from a soluble SO42– salt, is silver nitrate To explain, silver nitrate can be used to distinguish between the two The distinguishable observation is that Cl- salt will form a white precipitate and will SO42– form clear crystals Predict what would be observed (and why) from an aqueous mixture for each of the following (all substances are water soluble) a potassium carbonate and hydrochloric acid - It would produce a carbon dioxide gas leaving behind aqueous potassium chloride b zinc chloride and silver nitrate -It would produce a white precipitate of silver chloride c magnesium chloride and sodium hydroxide - It would produce a white precipitate if magnesium hydroxide since most hydroxides are insoluble d ammonium nitrate and sodium hydroxide - It would produce ammonia gas with an odor Three colorless solutions in test tubes, with no labels, are in a test tube rack on the laboratory bench Lying beside the test tubes are three labels: silver nitrate, AgNO3; hydrochloric acid, HCL; and sodium carbonate, Na2CO3 You are to place the labels on the test tubes using only the three solutions present Here is your analysis procedure: • A portion of test tube added to a portion of test tube produces CO2 • A portion of test tube added to a portion of test tube produces a white silver carbonate precipitate a On the basis of your observations, how would you label the three test tubes? Test tube 1: HCl Test tube 2: Na2CO3 Test tube 3: AgNO3 b What would you expect to happen if a portion of test tube is added to a portion of test tube 3? - If a portion of test tube is added to portion of test tube 3, we would get a AgCl and acid HNO3 Because AgCl is slightly soluble, this experiment will have a precipiate For individual solutions of the cations Ag+ , Ba2+ , Mg2+, and Cu2+ the following experimental observations were collected Ag+ Ba2+ NH3 No change No change HCl White ppta No change H2SO4 No change White ppt Mg2+ Cu2+ White ppt No change No change Blue ppt/deep No change No change blue soln with excess From these experimental observations, a Identify a reagent that distinguishes the chemical properties of Ag+ and Mg2+ What is the distinguishing observation? - A reagent that distinguishes the chemical properties of Ag+ and Mg2+ is NH3 The distinguishable observation is that Ag+ produces no distinguishable observation and Mg2+ produces a white precipitate b identify a reagent that distinguishes the chemical properties of HCI and H2SO4 What is the distinguishing observation? - A reagent that distinguishes the chemical properties of HCI and H2SO4 is Ag+ The distinguishable observation is that HCl produces a distinguishable white precipitate observation and H₂CO₃, SO produces a no distinguishable observation C identify a reagent that distinguishes the chemical properties of Ba2 and Cu2 What is the distinguishing observation? - A reagent that distinguishes the chemical properties of Ba²+ and Cu2+ is NH3(aq) The distinguishable observation is that Ba²+ produces a distinguishable white precipitate observation and Cu²+ produces a blue precipitate D identify a reagent that distinguishes the chemical properties of Cu2+ and Mg2+ What is the distinguishing observation? - A reagent that distinguishes the chemical properties of Mg2+and Cu2+ is NH3(aq) The distinguishable observation is that Mg2+ produces a distinguishable white precipitate observation and Cu²+produces a blue precipitate 6 Three colorless solutions in the test tubes, with no labels, are in a test tube rack on the lab bench Lying beside the test tubes are three labels: 0.10 M Na2CO3, 0.10 M HCl, and 0.10 M KOH You are to place the labels on the test tubes using only the three solutions present Here are your tests: • A few drops of the solution from the test tube added to a similar volume of the solution in the test tube produces no visible reaction but the solution becomes warm • A few drops of the solution from the test tube added to a similar volume of the solution in test tube produces carbon dioxide gas • Identify the labels for test tubes 1,2, and Test tube 1: 0.10 M HCl Test tube 2: 0.10 M KOH Test tube 3: 0.10 M Na2CO3