During the next step, error may have occurred if there was copper precipitate left on the side of the beaker instead of washed with water. Some precipitate is always lost when supernatant liquid is separated from the precipitate. During the stirring, there were blue precipitates in the beaker floating in the mixture. At different stages of the cycle, copper was present in different forms. The synthesis of copper metal is most relevant when it is done using various series of reactions and making complexes. Lots and lots of reagents are clear liquids, and very many chemicals form white solids, which makes it difficult to distinguish between them in the absence of a label. If the solid hasn't disappeared after you've added the amount of reagent calculated, however, try the following in this order.
Afterwards, I added sodium hydroxide, and my solution colored to a dark blue solution called copper hydroxide. Decantation can produce error so we should use some other filtration technique to obtain precipitates. It can never be broken down into differnet substances by normal chemical means. The error in this step was caused by the variable heating of the solution to prevent bubbling of the solution. Sources of Error: Throughout the entirety of the lab, there were many steps that presented possible sources of error such as adding too much reagent and less in copper solution, or it might be possible that precipitated are stuck with stirring rod, which can cause the error in reading. Add a little more reagent in small aliquots to the remaining solid in a beaker until it dissolves. If you choose to handwrite any part of the report, you must do so legibly in ink.
When the CuO was washed, the excess hydroxide ions that could have remained from the previous reaction were removed. Error may have occurred at this step if the balance that was used to weight the copper was not calibrated correctly, or if the amount of copper weighed was not exactly the 2 g required. The cycle of reactions was completed with the reaction where elemental copper was regenerated by Zn and Cu exchanging states in acidic solution. After the lab was finished, the final mass of the copper was 6. After 5 more minutes it dries up but there was no specific color change and it remain yellow. So then how could the final mass possibly be larger than the initial mass? Data and Calculations: The experiment is divided into two parts Part A and Part B.
The length of heating could also cause error as solution would need more 5 minutes to react completely with reagent. Add a magnetic stir bar and place on a heatable stir plate. Add approximately 25mL of deionized water into second beaker to remove any remaining copper ion traces and place rinse into first beaker with nitric acid. Remove the beaker from the heat and allow to cool. This was done through five chemical reactions involving copper.
If any blue color remains after the zinc has been consumed, add approximately 0. Place the 250 ml beaker on a hot plate and occasionally stir the mixture during heating. Ascorbic Acid White in color 0. Copper has been one of the most useful metals for over 5000 years. When the time came to evaporate the solution, the liquids disappeared, leaving behind a wet, brownish solid in the middle of the beaker. Before you start your work for the day, reserve a page or two in your notebook with space to record notes for each reaction in the cycle, recording things like the following. Another aspect of predicting products is the chart of reactivity.
Beakers are convenient containers for solutions and reactions, but they are not used for accurate measurements of volumes. Preparation of CuO: This step is completed using Bunsen burner. The shape of Cu metal is distinct clumps of Cu metal in solution and can be clearly seen in the clear transparent solution. Once cooled, pour the mixture into the Buchner funnel to filter the precipitate. The Feather Online Sophomores left to right Adalyn Richardson and Hannah Villines participate in the copper cycle lab, Jan. The products of the reaction were solid copper and aqueous zinc sulfate. Rinse any solids from beakers into the funnel with a generous amount of water.
When aqueous sodium hydroxide was put into the aqueous copper nitrate, copper hydroxide immediately crashed from the solution into a blue solid and it is in the beaker with aqueous sodium nitrate. And for the first we are using the analytical balance which is accurate as 0. The reaction between copper and nitric acid is an exothermic reaction. Add 40 mL of deionized water into a second clean beaker and begin heating. This experiment is very dangerous because of the reactions between the strong acids and bases. Remember to turn the vacuum on before adding anything to the funnel. Tips for column writing: 1 Write about interesting topics or angles that draw a reader into the column.
In the experiment we observed the every reaction which leads to compound and complex formation. We started our experiment with 2. If the solid is not completely dissolved the first time, replace the collection beaker with a clean new one and pour the acid in the first beaker through the filter again. In step 2 decantation process is used to separate the precipitate which is biggest source of error as we can lose some amount of precipitate and some water can still be there in beaker which will react with reagent during the reaction of copper solution. Experimental Procedure: The procedure was the same as that given in the lab manual. Purpose: The purpose of this experiment is to demonstrate a cycle of reactions involving copper.
The copper cycle is evidence for the Law of Conservation of Mass, which states that an element or matter can never be created or destroyed, only changed. Caution: This reaction is initially vigorous. If it is not bright and shiny, clean it with a piece of steel wool, rinse with water and dry with a paper towel. Record your observations in your notebook. Your lab report must be submitted using this official report sheet. Once the reaction is complete and no more solids are obtained, combine the solids into one Büchner funnel to wash them.