In this lab, one piece of evidence that showed a double displacement reaction occurred was when a solid (precipitate) was formed. This is evident in the reaction between sodium sulphate and barium chloride. One of the products in this reaction was barium sulphate which is a white precipitate in an aqueous solution. This precipitate is definite evidence of a chemical reaction. Another characteristic that showed a double displacement reaction occurred was when a gas was produced. This is evident in the reaction between sodium carbonate and hydrochloric acid. One of the products is hydrogen carbonate which decomposes to carbon dioxide and water. Carbon dioxide is a colourless gas that indicated a chemical reaction occurred. Another piece of evidence …show more content…
After performing the lab, it is evident that one of the indicators of a double displacement reaction is the formation of a precipitate in an aqueous solution. This was seen through two of the reactions performed in this lab; sodium sulphate with barium chloride and lead (II) nitrate with potassium iodide. In the reaction between lead (II) nitrate and potassium iodide, both of the solutions were transparent liquids before they were mixed. However, after the solutions were mixed, a dark yellow precipitate formed within the aqueous solution. This indicated a chemical reaction occurred in this double displacement reaction. Another property that indicates a double displacement reaction occurred is the formation of gas. This was seen through three of the reactions performed in this lab; sodium carbonate with hydrochloric acid, sodium carbonate with sulphuric acid, and sodium hydroxide with ammonium chloride. In the sodium hydroxide and ammonium chloride reaction, when the two solutions are mixed, bubbles began to form rapidly. This clearly indicated that a gas was released when the reactants were mixed. Lastly, a property that indicates a double displacement reaction occurred is a temperature change. This is seen through the reaction between sodium hydroxide and sulphuric acid. In this reaction, the acid and the base combined to form a colourless solution. However, it was observed that the reaction released heat indicating a chemical reaction occurred. After observing the chemical equation, the anion from the acid and the cation from the base combined to form a salt and water, a neutralization reaction. Thus, it can be concluded a neutralization reaction is an indicator of a double displacement reaction. The property that indicated a double displacement reaction did not occur was when the products of
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.
Double Replacement Lab Report Date Completed: October 8, 2015 Objective To analyze and determine if a chemical reaction occurred between two compounds using the concepts we learned in class. Also, if the chemical reaction occurred, to determine if it formed a precipitate or gas. Safety General Safety Precautions: Do not touch the chemicals Use of gloves and coats are recommended, use of goggles should be required Keep the work area clean Dispose of the chemicals properly, DO NOT dispose them in the sink Clean up your work station Wash your hand before and after the lab Make sure all chemicals are labeled correctly NEVER return chemicals to reagent bottles Use the wafting technique to smell the chemical Clean up spills immediately
Identification of an Unknown Compound using Quantitative and Qualitative Analysis Lauren Tremaglio Chemistry 1011 Lab, Section 16 Instructor: Steven Belina October 3, 2014 Our signatures indicate that this document represents the work completed by our group this semester. Experimental Design and Discussion of Results The objective of this experiment was to identify an unknown compound through quantitative and qualitative analysis. In order to find the identity of the unknown compound, an initial qualitative test for solubility was performed.
To test for the presence of the carbonate (CO32-) anion, a small scoop of the unknown compound was mixed with
The compounds tested in included the unknown, Calcium Nitrate, Calcium Chloride, Calcium Carbonate, Sodium Chloride, Potassium Chloride, Magnesium Chloride, and Ammonium Chloride. The next test was the pH test. In this test, the aqueous solutions from the flame tests were used again. A piece of pH paper was dipped into the aqueous solutions, a different piece for each solution. The ensuing coloration of the paper was compared to the pH scale and the
The heating of the solution caused the reaction to start which decomposed Cu(OH)2 and made the solution colorless and darkened the precipitate. The fourth step was the formation of CuSO4. After the solution was decanted from the precipitate and washed with near boiling water, 6 M H2SO4 was added to the beaker containing Copper (II) Oxide and this caused the precipitate to dissolve and the liquid become clear blue. The last step was the formation of Cu(s). This step recovered Solid elemental copper.
1. What type of macroscopic evidence for chemical change did you observe during this experiment? Give at least three different examples. (15 points)
One of the reactions you observed resulted in this product: NaCl + H2O + CO2 (g)? What well did this reaction occur in? Describe how the observations for this reaction support your answer. B BoldI ItalicsU Underline Bulleted list Numbered list Superscript Subscript70 Words A reaction I observed in number 1.)
In an experiment, physical changes and chemical changes occur. A physical change changes the visible appearance, without changing the composition of the material, and examples include as boiling, melting, cutting, and dissolving. On the other hand, chemical change changes where a new form of matter is formed and is irreversible, such as rusting, burning, decomposition, and cooking. Although no example of chemical change was given by any source, there is one example of physical change. A physical change with Carmustine is decomposition, according to The Cytotoxics Handbook (Allwood, Stanley, and Wright 282).
They occur when two ionic compounds are used as reactants and the anions and cations switch places between the two. This type of reaction will proceed provided that the reactions do not have the same cation or anion as explained in discussion question #3. Also, the products of the reactants must have at least one solid to indicate a precipitate is made. If all products are aqueous then the reaction did not take place as shown by the fourth reaction presented in discussion question #5.
Introduction: The purpose of this experiment is to demonstrate the different types of chemical reactions, those including Copper. There are different types of chemical reactions. A double displacement reaction is a chemical process involving the exchange of bonds between two reacting chemical species. A a decomposition reaction is the separation of a chemical compound into elements or simpler compounds and the single-displacement reaction is a type of
Throughout the experiment, copper was altered a total of 5 times, but after the final chemical reaction, solid, elemental copper returned. Each time the solution changed color, a precipitate formed, or when gas appeared, indicated that a chemical reaction was occurring. For the first reaction, copper was added to nitric acid, forming the aqueous copper (II) nitrate (where the copper went), along with liquid water, and
The flame test produced inconclusive results because we were unable to determine whether the flame produced a faint orange tint or no color. Next we tested the pH change that the compound caused in water to determine its solubility. Our known compound did not dissociate or dissolve in water, instead it formed a white colored precipitate, therefore that eliminated a lot of the choices from the unknown compound list. In addition, when we performed the acid test, the unknown compound bubble which revealed it must be a carbonate. The previous test reveal it did not dissociate in water, therefore the only option from the list it could be was
Then the balloon is lifted up so that the baking soda runs into bottle to react with the vinegar inside. Immediately the balloon is inflated by the carbon dioxide formed. The baking soda is kept constant when the experiment is repeated for another different amount of vinegar. Results/Findings When sodium bicarbonate and vinegar mix,
The chemical equation for this experiment is hydrochloric acid + sodium thiosulphate + deionised water (ranging from 25ml to 0ml in 5ml intervals) sodium chloride + deionised water (ranging from 25ml to 0ml in 5ml intervals) + sulphur dioxide + sulphur. As a scientific equation, this would be written out as, NA2S2O3 + 2HCL + H2O (ranging from 25ml to 0ml in