What are the identities of the substances found after electrolysis and heating? The identities of the substances found were Iodine, Iodide ion (I-), Triodide ion(I3-), Zinc metal and Zinc ion(Zn2+) Post Lab questions: 1. What did this experiment convincingly show about the composition of the white solid? I put that the experiment showed us the white substance was comprised of Zinc ions and iodide ions, and that the two ions and be separated back into their respective elements 2. During the electrolysis, a gray solid formed on the negative wire of the battery and the dark red solution formed at the positive wire of the batter.
The following data were obtained when a sample of barium chloride hydrate was analyzed as described in the Procedure section. Calculate (a) the mass of the hydrate, (b) the mass of water lost during heating, and (c) the percent water in the hydrate. Mass of empty test tube 18.42 g Mass of test tube and hydrate (before heating) 20.75 g Mass of test tube and anhydrous salt (after heating) 20.41 g. Mass of the Hydrate is 2.33g. Loss (H2O) is 0.34g. Percent H2O in Hydrate is equal 0.34/2.33=14.6% 3.
The reaction that occurred with this step was displacement and metathesis in the form of gas formation. The balanced equation of this step looks as follows: CuSO4aq+Zns→Cus+ZnSO4(aq) Once this step was finished, the remaining copper was retrieved. First, to recover the copper HCl was added to remove all the zinc. When this happened, a yellow tint was observed in the liquid, as well as bubbling as the zinc was broken down. Once the copper dried out, it was weighed and came to a total of 240 mg.
Objective: To observe the physical properties of solids containing: ionic, polar covalent, nonpolar covalent, network covalent, and metallic bonds. Thus, being able to classify unknown solids into the appropriate bonding categories based on their physical properties. Materials: - Test tubes - Test tube clamp - Bunsen burner - Distilled water - Conductivity probe - A spatula - One compound from each category (ionic, polar covalent, nonpolar covalent, network, and metallic) - Acetone/hexane mixture - Parafilm Methods: One compound from the following compounds was obtained from the professor: ionic, polar covalent, nonpolar covalent, network, and metallic. The following tests were carried out on each sample and the observations were recorded. For the metal sample, only steps one and five were conducted.
Jessica Atanova CHEM 104 lab 03/10/14 SUBSTANCES Granular zinc- gray crystal like | Iodine crystals- dark, circular, rock-like | De-ionized water: used for standard Zinc Ion procedure. | Materials: Boiling tube: for products. | Small test tubes: used to centrifuge the solution and precipitate | Graduated cylinder: used for measurement of water | Stirring rod: used various times to stir samples and solutions. | Spatula: used to measure and transfer the substances. | Centrifuge: used to isolate the solid from the solution | .
Contents Abstract – Page 2 Summary of Results – Page 3 Focus Question – Page 5,6 What if… - Page 6 Confidence Report – Page 7,8 Abstract Summary of Results Observations of Reactions – Trials 1 , 2 & 3 | Dissolving Barium Iodide and Zinc Sulfate in deionized water | As the substances dissolve the water becomes cloudy and acquired a white tint. | Centrifuging up the solution obtained in previous reaction | The precipitate and the liquid seperated, and there was more precipitate in one of the test tubes. The precipitate was a thick white color, not transparent. | Heating the Precipitate in a boiling tube containing 2 boiling chips | The mixture began producing a large amount of bubbles, as we continued heating it only white powder remained. | Observations of Chemicals | Zinc Sulfate | Powder of a white solid | Barium Iodide | Powder of a white solid.
SEPARATION OF A MIXTURE OF SUBSTANCES LAB Purpose: Every chemical has a set of defined physical properties, and when combined they present a unique fingerprint for that chemical. When chemicals are present in a mixture, these unique physical properties can be utilized to separate the chemicals into their pure states. This experiment will give you experience in separating the components in a three-compound mixture; ammonium chloride, sodium chloride (table salt), and silicon dioxide (sand). Background: Because there are 3 components in our mixture, we will need several techniques to separate them. For this particular exercise, you should be familiar with the following: • Sublimation: Many chemicals will sublime (phase change from solid state to gas state) provided the right conditions.
Computer Additivity of Heats of Reaction: Hess’s Law 18 (1) Solid sodium hydroxide dissolves in water to form an aqueous solution of ions. (2) Solid sodium hydroxide reacts with aqueous hydrochloric acid to form water and an aqueous solution of sodium chloride. NaOH(s) + H+(aq) ) + Cl–(aq) → H2O(l) + Na+(aq) + Cl–(aq) ∆H2 = ? OBJECTIVES • • • • In this experiment, you will Combine equations for two reactions to obtain the equation for a third reaction. Use a calorimeter to measure the temperature change in each of three reactions.
There are two parts to this lab. Part 1 which will be a known hydrate CoCl2 ∙6H2O or Cobalt (II) Chloride hexahydrate, and Part 2 which will be an unknown hydrate. Equations and Mechanisms * Moles of hydrate and water ratio: Moles of water Moles
Observations of Physical and Chemical Changes Purpose- The different tests can interact and change in different ways, by doing these tests we can figure out if it could be either a physical change or chemical change by observing the test and chemicals. Procedure- In test one, you mixed a small amount of iodine in each test tube and fill one of the with just tap water and the second one with hexane. Test two, you measure 5 grams of barium hydroxide and same measurement of ammonium chloride and stir with a stirring rod. Test three, you use a small piece of steel wool and you place it over a Bunsen burner using tongs and observe what you see. Test four, by using a plastic bag, you place a spoon full of calcium chloride in one corner and