Cassie Droelle 1510-01501 Chemical Equation 2 Visualizing Stoichiometry – Inquiry Lab Cassie Droelle 1510-01501 4-18-16 Introduction The purpose of this lab is to determine the complete balanced equation of a metathesis reaction with an unknown metal ion by first experimentally identifying the metal ion and then using stoichiometry to determine the rest of the equation. Stoichiometry is “the process by which quantities in a chemical reaction are compared” and is based on the Law of Conservation of Mass (1). The Law of Conservation of Matter “dictates that the mass of the reactants and mass of the products must be equal” (1). This is accomplished with the use of coefficients to keep the number of atoms consistent on …show more content…
The possibilities for the identity of the metal include copper and iron (1). The possible charges for copper are 1+ and 2+ (2). The possible charged of iron are 2+ and 3+ (2). By using stoichiometry, it can be concluded that there are only four possible equations: CuNO3 (aq) + NaOH (aq) > NaNO3 (aq) + CuOH …show more content…
If the ion is in solution, NaOH can be added and if a blue precipitate is formed the metal ion is copper (1). A flame test can also be used to identify the metal ion. Copper burns blue-green (1) and iron burns gold (3). A quantitative test can be used to then determine the charge of the metal ion. By performing the reaction with different ratios the charge of the metal ion can be determined. The ratio of Metal (?) Nitrate to NaOH in the first equation is 1 to 1. The ratio in the 2nd and 3rd equations are 1 to 2 and the ratio in the 4th equation is 1 to 3. Therefore, when the reaction is performed these are the reactant ratios that must be used in order to determine the charge of the ion. If the qualitative test identifies the metals and the quantitative test identifies the charge of the metal, then there should only be one possible equation left from the four above, because each equation has a unique metal ion.
An error that could have been present during the lab includes not letting the zinc react completely with the chloride ions by removing the penny too early from the solution. For instance, the percent error of this lab was 45.6%, which was determined by the subtraction of the theoretical percent of Cu 2.5% and the experimental percent of Cu 3.64% and dividing by the theoretical percent of Cu 2.5%. This experiment showed how reactants react with one another in a solution to drive a chemical reaction and the products that result from the
After copper ions were filtered, approximately 15mL of .5 M was added to the filtrate, which made the mixture acidic. Then, 20 mL was added into the filtrate to raise the pH of the mixture.
Chemical Reactions and Identifications of Unknowns Data Analysis Name: _Gloria Smith_________________________________________ Please answer the following questions with complete sentences unless a fill in the blank is given. Your answers must be typed. Do not plagiarize! Identification Tests: Flame tests are used to identify the __metal ions_ of a compound. Litmus paper is used to identify acids and bases.
One must look to see which element has both violet and orange spectra lines. It is shown that the element Cesium is the only element that has both violet and orange spectra lines. 2. Describe two different approaches to exciting the electrons that exist in elements. Offer a specific reason why scientists use different approaches to excite the electrons of different elements.
Metal cations can be identified based on the colors they emitted off when heated in a flame.1 When atoms of the ions that were tested are excited, their electrons move up to higher levels of energy.2 When the electrons relax and return to the original states, they emit photons of specific energy creating wavelengths of light that produces colors.3 The test wire and Bunsen Burner were used to excite the solution in the crucible. The standard metal cations that were tested and their outcomes are as shown in Table 1.
Scientist preform many qualitative analyses to determine the identity of an unknown ionic compound. The determination of the compound involves preforming a series of test and using a high level of logical thinking. In the project unknown cations and anions were tested to determine each identity. Once the identity was determined logic trees for each, the cation and anion, were constructed to help identify the unknown compound.
The insoluble precipitate, AgCl, is a solid. NaNO3 is aqueous because it's soluble in water. AgCl precipitated out of the solution because it's insoluble in water (7). If an ion is insoluble, then it forms a solid with an ion from the other reactant (7). The chemical equation
It is malleable, ductile, and a good conductor of heat and electricity (second only to silver in electrical conductivity). Its alloys, brass and bronze, are very important. However, to understand the structure and character of atoms of the element copper (Chemical symbol: Cu), one has to first gain knowledge on the three subatomic particles that make up copper atoms. Each atom is made up of electrons, neutrons, and protons.
In this experiment, the ions that go through gravimetric analysis are the copper and sulfate ions (Grossie and Underwood, 25). Elemental analysis involves determining the amount, which is usually a percent, of an element present in a compound (Blauch, 1). In this experiment, the element going through the elemental process hydrogen, in which the percent of the compound is attempted to be found (Grossie and Underwood, 25). In order to find the amount of copper, copper oxine needs to be formed. To find it, there is a reaction of hydrated copper sulfate and oxine, producing copper (II) oxine (Grossie and Underwood, 25).
The zinc will form a new compound with the sulfate, and the copper will stay as a metal. Balanced Chemical
Stoichiometry is a method used in chemistry that involves using relationships between reactants and products in a chemical reaction, to determine a desired quantitative data. The purpose of the lab was to devise a method to determine the percent composition of NaHCO3 in an unknown mixture of compounds NaHCO3 and Na2CO. Heating the mixture of these two compounds will cause a decomposition reaction. Solid NaHCO3 chemically decomposes into gaseous carbon dioxide and water, via the following reaction: 2NaHCO3(s) Na2CO3(s) + H2O(g) + CO2(g). The decomposition reaction was performed in a crucible and heated with a Bunsen burner.
Verna Wang Hannah Palmer CHEM 101-069 Lab 11-19-16 Stoichiometry and Limiting Reagents Lab Report Purpose: We are using the reaction of sodium hydroxide and calcium chloride to illustrate stoichiometry by demonstrating proportions needed to cause a reaction to take place. Background: Just like a recipe would call for a specific amount of one ingredient to a specific amount of another, stoichiometry is the same exact method for calculating moles in a chemical reaction. Sometimes, we may not have enough of or too much of one ingredient , which would be defined as limiting and excess reagent, respectively.
To test this, add a small amount of broken down pieces of the sample into a beaker filled with 100ml of water. Stir the sample with a stir rod for 10-15 seconds to see if it dissolved completely, if yes, then the sample is soluble, if not then the sample is not soluble. Repeat all these steps for the other samples and the unknown sample. The samples that used is Copper (Cu), Lead (Pb), MAgnesium (Mg), Sulfur (S), Carbon (C), and two unknown samples which were later identified as Tin (Sn) and Iodine (I). Before we started the lab, my hypothesis was that Lead (Pb) will have a higher conductivity than Sulfur (S) because Sulfur falls in the semi-metal category whereas Lead is in the metal
The zinc acts as the anode and the copper acts as the cathode. Copper has a higher electronegativity than zinc, so the bonding electrons in zinc leave and flow into the copper. However, this reaction would not be possible without the lemon in the experiment, which acts as an electrolyte because it contains citric acid in the form of lemon juice. When the zinc comes in contact with the lemon juice, oxidation occurs within the zinc. Oxidation is a process where an element loses electrons in a chemical reaction.
Electrochemistry is the study of reactions in which charged particles (ions or electrons) appear in two phases of matter, such as the metallic phase (the electrode) or aqueous phase (the electrolyte). (Lower 2004) These reactions involve the transfer of electric charges between the electrodes and the electrolyte. These cells have two electrodes which are named the anode and the cathode. The anode is the electrode where oxidation occurs and the cathode is the electrode where reduction occurs (Electrochemical cells 2014).