A double replacement reaction took place in step 4 between the copper nitrate and sodium hydroxide.
However, in this experiment, the results were completely different due to human error and other sources of error listed below. After finding the net ionic equation of the reaction, one determined that the products of the reaction were solid copper and aqueous zinc ions.
If an transition metal ion has empty orbitals some electrons in d orbitals that are at a lower energy may transition or jump to open spots in d orbitals that are at a higher energy.
Therefore, when the copper was washed, the zinc ions were washed out with the water. In general, absorbance is proportional to concentration. The gas remains in the air, but it just changes forms.
There were many different sources of error throughout this lab, and I believe that this was the reason for such a significant difference between the initial and final masses and moles of copper that were calculated.
The copper was originally placed into a mL beaker rather than a mL beaker; therefore, after the sodium hydroxide was added to the solution, the new solution was transferred to the mL beaker, resulting in small fragments unable to be transferred to the mL beaker.
Place flask back in water bath, heat to boiling, and stir.
How many moles of electrons must be transferred to create g of copper. The reaction between copper and nitric acid is an exothermic reaction. During step 5, stirring of the mixture was required, so another source of error was that copper from the beaker may have been left on the stirring rod.
High temperatures, because the gas molecules are moving too fast to interact with each other 5. Correctly identify the anode and cathode in this reaction as well as where oxidation and reduction are taking place.
The product of the reaction between copper and nitric acid in step 2 is placed on ice in order to cool the solution. All in all, there was an abundance of sources of error in this lab.
Powered by Create your own unique website with customizable templates. Most of the zinc was obtained by heating a mineral, calamine, which contains several zinc compounds.
If there was any solid zinc that did not react with the copper sulfate and was left over with the copper precipitate, zinc particles may have significantly changed the mass of the final product.
The error in this step was caused by the variable heating of the solution to prevent bubbling of the solution. The N-H bonds within the NH3 molecules break apart. In addition to these metals, brass may also contain small amounts of iron, lead, aluminum, and tin. If the total pressure exerted by the gases is 2.
The hydroxide compounds were aqueous only sometimes, in the case of it being bonded to a group I metal. Which gas molecules will have the highest velocity and why.
However, in this experiment, the results were completely different due to human error and other sources of error listed below. Solid copper is found on the bottom of the beaker. Ions that did not participate in the reaction or change are called spectator ions.
These reactions add substances and take substances away, but copper remains in the reaction the entire time. When copper reacts with a strong base, in this case NaOH, the reaction forms metal hydroxides, and these reactions are replacement reactions.
In this lab, there was a redox reaction, a decomposition reaction, single replacement reactions, and double replacement reactions. While decanting, some members of the group could not differentiate the copper in the solution, mainly because solution was black and its components were not visible.
Powered by Create your own unique website with customizable templates. Therefore, when the copper was washed, the zinc ions were washed out with the water. The states of the substances had to be added in order to help identify what each substance was in the beaker. Also, when the copper was weighed to determine its final mass, there was a gelatin-like substance on the edges of the newly formed copper on the evaporating dish.
The hydrogen bonds holding separate NH3 molecules together break apart. Decant liquid from solid. Powered by Create your own unique website with customizable templates.
And it did have a profound affect on the measured final mass of copper, increasing it significantly. Therefore, when zinc was added to the new solution, not all of the copper was involved in the reaction and not all of the potential copper was produced.
The O2 molecules, because they have the least mass B. In this lab, chemical reactions also had to be written and balanced. Brass is a generic term for alloys of copper and zinc.
In addition to these metals, brass may also contain small amounts of iron, lead, aluminum, and tin.
Resources for my AP Chemistry students. Almost all of the handouts, practice exams, many answers, and a few tutorials reside here organized by chapter. General Chem is the link below. After sulfuric acid was added to the beaker, copper was found as copper ions with a 2+ charge instead of the previous copper(ii) oxide form.
6. In the final step of the lab when the copper precipitate was washed, zinc ions were removed. The previous reaction that took place involved aqueous copper(ii) sulfate and. If J of heat energy were used to heat up a gram sample of copper metal and a gram sample of water both starting at °C, calculate the final temperature of each sample?
Signs of (T and q: (q means heat is. released. + q means heat is South Pasadena · AP Chemistry. The yield from copper was extremely high; the final mass was greater than the initial mass of copper- a difference greater than ten.
The previous could be the result of a large quantity of zinc still being present in the evaporating dish when the copper was measured. AP’s high school Chemistry course is a rigorous, college-level class that provides an opportunity to gain the skills and experience colleges recognize.The chemistry of copper ap chemistry