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The percentage of copper and oxygen in samples of CuO obtained by different methods were found to be the same. The illustrate the law ofSelect an answerAconstant proportionsBconservation of massCmultiple proportionsDreciprocal proportions

Question

The percentage of copper and oxygen in samples of CuO obtained by different methods were found to be the same. The illustrate the law ofSelect an answerAconstant proportionsBconservation of massCmultiple proportionsDreciprocal proportions

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Solution

The correct answer is A. constant proportions. This is because the law of constant proportions, also known as the law of definite proportions, states that a chemical compound always contains exactly the same proportion of elements by mass. So, no matter how you obtained the samples of CuO, the percentage of copper and oxygen in them would be the same.

Similar Questions

The percent composition by mass of copper and oxygen in copper(I) oxide is determined to be  % copper and  % oxygen. Round your answers to two decimal places.M Cu = 63.55 g mol-1M O = 16.00 g mol-1

Copper can also be produced by the reaction of carbon with copper(II) oxideaccording to the equation2CuO + C → 2Cu + CO 2Calculate the percentage atom economy for the production of copper by thisprocess.Give your answer to the appropriate number of significant figures.

The experiment involved a series of reactions to produce copper solid from the copper compound copper chloride dihydrate. The proportion of copper in CuCl2.2H2O was 0.0588g and the final mass of copper solid recovered was 0.0165g. Therefore, the percentage yield calculated was 28.1% suggesting a large percentage of copper was lost. An alternative reaction pathway such as replacing zinc powder with a stronger reducing agent like aluminium or magnesium could increase the yield of copper as it reduces copper ions more effectively. The colour changes observed during the experiment are the result of the varying oxidation states of copper and the formation of different copper compounds. The experiment started off with a blue-green powder of CuCl2.2H2O which turned into bright blue transparent solution after being dissolved in water. The addition of NaOH produced a light blue precipitate in solution indicating the formation of Cu(OH)2. Upon heating the solution, the precipitate transformed into a black solid, CuO. Then, H2SO4 dissolved the CuO, producing a transparent and light blue solution of CuSO4. Finally, the copper ions in solution were reduced by zinc powder, forming a reddish-brown copper solid. The experiment includes the process of decantation between copper solid and the supernatant. During this procedure, some copper solid was lost when the supernatant solution was separated from the precipitate. This could have been due to the incomplete separation of the solution and the precipitate which could have led to the loss of copper solid recovered (final mass) and therefore reduction of percentage yield. Another possible source of error could be that the reaction between CuSO4 and Zinc powder was incomplete. This indicates that the amount of zinc added to the solution was less than the stoichiometric amount required to completely displace all the copper ions. As a result, the actual amount of copper solid produced was less than the theoretical yield. This discrepancy reduced the percentage yield of copper. Overall, the low percentage yield of copper obtained suggests this method was inefficient at extracting copper from copper compounds. The experimental method was too complex, time-consuming, and required a significant number of reagents which would make it economically and environmentally impractical for the large-scale extraction of copper from ores. Alternative methods may need to be considered for commercial purposes. Reduce the above paragraph to 300 words

The cycle of copper reactions starts with solid copper metal and ends with solid copper metal.Suppose you start with 0.489 g of Cu. After performing all the reactions, you have 0.478 g of Cu. What percentage of the copper did you recover?Type answer:

Explain the following statement by providing an example from the table.CuO and Cu2O are both compounds of copper and oxygen but they do not have the same properties.

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