Answer:
Here... Since there is excess HCl, you know the Zinc will be the limiting reagent. I was able to create the reaction equation based on the info you gave: Z + 2HCl ----> ZCl2 +2H. Now, in order to find the theoretical yield of ZCl, you need to convert Zinc from grams to moles. Do this by dividing by its molar mass (65.38), thus: 3.68 (g) / 65.38 (g/mol) = 0.056286... moles.
Now, using the balanced equation we made earlier, we see that 1 mole of Zinc creates 1 mole of ZCl2. Thus our ratio is 1:1. This makes the next step easy. Since it is 1:1, we multiply the number of moles we have of Zinc (0.056286...) by the number of moles it will create of ZCl (1). (0.056286)(1) = 0.056286 moles ZCl. Now convert this to grams by multiplying by its molar mass (136.28) and you get 7.67 grams. This is your theoretical yield. The percent yield is found by dividing the actual amount obtained (7.12 g.) by the theoretical yield (7.67 g.) then multiply that by 100%. When this is done, your Percent Yield is about 92.8%
Answer:Hope this helps!
Explanation:
You can use a flame test to help identify the composition of a sample. The test is used to identify metal ions (and certain other ions) based on the characteristic emission spectrum of the elements. The test is performed by dipping a wire or wooden splint into a sample solution or coating it with the powdered metal salt. The color of a gas flame is observed as the sample is heated. If a wooden splint is used, it's necessary to wave the sample through the flame to avoid setting the wood on fire. The color of the flame is compared against the flame colors known to be associated with the metals.
<span>the answer would be chemical</span>
Answer:
B.) An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom loses the electron.
Explanation:
Silicon is located in the 3rd row and 14th column in the periodic table. Arsenic is located in the 4th row and 15th column in the periodic table. This means that arsenic has one more valence electron than silicon. Since arsenic is located one row down from silicon, its valence electrons occupy higher energy orbitals.
Silicon maintains a crystal-like lattice structure. Each silicon atom is covalently connected to assume this shape. When silicon gains one extra electron from arsenic, it experiences n-type doping. This new electron is not tightly bound in the lattice structure. This allows it to move more freely and conduct more electricity. This can also be explained using band gaps. Silicon, which previously had an empty conduction band, now has one electron in this band. This lowers the band gap between the conduction and valence bands and increases conductivity.
