1.) is my answer in the 7-8 correct? 2.) Please help me with Question 1 in the b

Question

1.) is my answer in the 7-8 correct? 2.) Please help me with Question 1 in the bottom

F17 PROCEDURE I. Weigh -0.5 g copper oxide onto a piece of tared weighing pa Record the actual mass in your )2 notebook. Transfer the copper oxide to a 150 mL beaker and add 20 m 2. Stir with genutle heating untilthe solid has completely dissolved. This may a second sample and stir it more. While the first sample is dissolving, repeat step I to prepare with gentle heating as well. Record your observations as the samples dissolvevel sample is fully dissolved, obtain a zine strip and a piece of sandpaper. Sand the surface Place the zinc strip in the of the zine strip to remove copper solution. Record your observations over the next 10-20 minutes. the oxidized zine and expose shiny metal. Gas 4. Occasionally stir the solution with a glass stirring rod until the solution is colorless. evolution may still occur (the HCI will also dissolve the zinc strip over time). Use tongs to remove the zine strip from the solution. If any copper metal has adhered to the zine strip, scrape it back into the beaker. Rinse the zine strip with water, dry with a paper towel and return the zine strip and the sandpaper to the supply hood. Do not throw the zinc or the sandpaper away because they can be reused! 5. Decant the supernatant off into a waste beaker. water and decant off the water. Wash the solid copper precipitate with 20 mL DI Remove Wash a second time with 20 mL water and decant off. as much water as possible. Finally, wash two more times with 5.0 mL of ethanol and decant. (There are a total of 4 washes means to gently pour off the supernatant while leaving the solid in the beaker. two with water and two with ethanol) Note: DECANTING 6. After the washings, put your initials on the beaker containing the copper precipitate and your TA will set it in the oven to dry for about 15-20 min. When it has been removed from the oven let it cool and record the mass of the beaker and contents. Put the beaker back into the oven for another 15-20 minutes and once it has been removed and cooled again record the mass of the beaker and contents. Repeat as needed. Once the mass is constant (two consecutive mass measurements are the same), the copper is dry. Care must be taken in this step not to overheat

Explanation / Answer

8) The crude empirical formula in Trail 1 = Cu1O2.12

The crude empirical formula in Trail 2 = Cu1O1.64

The solution to the 9th part is exactly correct.

1. In general, the decanted solution should be colorless.

If the decanted solution in step 5 is not colorless, that will indicate that some of the precipitates also got transferred while decanting the solution.

As a result, the mass of the actual precipitate and its no. of moles decreases.

Hence, the empirical formula would be affected, where the suffix of O (oxygen) increases.

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