In part one of the lab we used a micro scale technique to derive an activity series for metals. With the use of this technique we measured the same amount of different metal nitrate solutions into each well. Then we placed a piece of metal in the other metal nitrate solutions. With the data we recorded we resulted our activity series for the metals. We resulted that lead, silver, and copper are the strongest oxidizing agents, and that magnesium and zinc are the weak oxidizing agents.
Calculate the percent error in the molar mass value. Enter both values in the Data Table. Molar Mass Na2CO3 = 105.99 g/mol – this is the closest molar mass to what I calculated, so the unknown M2CO3 must be sodium carbonate. Percent Error: 93.08g/mol – 105.99 g/mol (100) = 12.18% error 105.99 g/mol DISCUSSION Review the procedure and list the possible sources of error that would cause either the molar mass of the unknown to be (a) too high or (b) too low. The goal of this lab was to discover the unknown group 1 metal (M) of the compound M2CO3 by dissolving the compound in water and adding a solution of calcium chloride, CaCl2 to the solution in order to precipitate the carbonate ions to reveal the molar mass of the unknown element, thus determining the identity of the unknown element.
Through our identification tests, we identified the gray solid to be zinc granules, the colored solution to be zinc ion and iodine-iodide-triiodide ion in water and the white solid to be solid zinc iodide. These identifications compared well with two other groups data. Ismat Zerin and Savita’s group also identified these substances to also be zinc granule, zinc ion and iodine-iodide-triiodide ion in water, and zinc iodide. Even though our conclusion was the same, our identification results did differ to some extent. For the identification test for the gray solid, we all concluded that this substance showed negative results for every chemical tested except for the zinc metal.
The term Cp is the specific heat of the material (at constant atmospheric pressure). Different materials have different specific heat values. The units of specific heat are : Joules/gram deg – C. In this lab we will find the specific heat value of Zinc and compare it to accepted values.This will do by heating a mass of Zinc up to the temperature of boiling water and placing the hot metal into a cup of cold water. The thermal energy that the zinc loses goes into heating up the water in the cup. By knowing the starting temperatures and the final temperature of the water and the zinc, the specific heat of Zinc may be easily obtained.
Carefully insert a piece of lead into the zinc nitrate. Record your observations. 10. Carefully insert a piece of lead into the iron (III) chloride. Record your observations.
Sample 1 2 3 Average DDT (ppt) 0.3 0.8 0.4 0.5 PCB (ppt) 0.9 0.4 0.7 0.7 Dieldrin (ppt) 0.3 0.6 0.1 0.4 We finished part I by testing the dissolved oxygen in the water. Our analysis sample shows an average of 9.5ppm dissolved oxygen in a 17 degree Celsius and the normal levels of dissolved oxygen are between 1-10ppb, which suggests the concentration was not harmful to the fish. The results in part one show that the lead and iron were toxic to the fish but it’s not clear on which was the major
EXPERIMENT 10: Solubility of Ionic Compounds Aim: How can we determine the solubility rules of ionic compounds? Materials: dropper bottles containing aqueous solutions of CaCl2, NaI , Na3PO4, AgNO3, CuSO4, NH4OH, , NaOH, and Na2CO3, plastic spot plates Introduction: A precipitation reaction occurs when two ionic compounds react in an aqueous solution to produce a precipitate, an insoluble (not soluble) substance which falls out of the solution. These reactions are a type of double-replacement, because the cations and anions of the reactants “change partners” in the products. For example: AgNO3 (aq) + NaOH (aq) ( AgOH (s) + NaNO3 (aq) According to Reference Table F, salts with hydroxide ions (OH-) are usually insoluble, and the silver ion (Ag+) is not an exception to this rule, so the AgOH that is formed will precipitate. However, in many instances, no precipitate forms because the recombination of ions yields only soluble compounds.
For zinc ion to react, the NaEDTA must also be an ion in the solution which means that the large salt must be dissolved in water. Procedure 1) Weighed out 3.64 of NaEDTA on an electronic beam balance 2) Added this mass of NaEDTA using wide mouth funnel to a 250 mL volumetric flask. 3) Rinsed the funnel with a squirt bottle containing deionized water making sure none of the solid remained in the funnel. 4) Added about 100-200 mL of deionized water to the volumetric flask containing the solid NaEDTA. 5) Swirled the solution until the NaEDTA (s) dissolved entirely.
Chemistry GCSE Modules C4, C5 and C6 C4: Chemical Patterns A: The periodic table • Relative atomic masses are the masses of atoms in comparison to the lightest atom, hydrogen, on a scale where hydrogen is 1. • Groups of three are groups of atoms with similar properties, where the relative atomic mass of the middle element is the mean of the relative atomic masses of the other two elements, for example calcium, strontium and barium is a group of three. • A periodic pattern is a repeating pattern. • On a periodic table: o A period is a row, and starts with a reactive metal and ends with a noble gas. o A group is a column, and contains elements with similar properties.
Synthesis of Colloidal Ag Colloidal silver is made by adding an excess of the reducing agent sodium borohydride, NaBH4 to silver nitrate, AgNO3 . AgNO3 + NaBH4 → Ag + 1/2H2 + 1/2B2H6 + NaNO3 The method used in the procedure for this experiment produces nanoparticles that are about 10-14 nm in diameter. The transmission electron microscope (TEM) image shown corresponds to a sample of silver nanoparticles with diameters that are 12± 2 nm. (The length bar is 20 nm.) Particle size can also be determined using visible spectroscopy.