2. A student used a piece of aluminum that had a mass of 2.583 grams, and treated according to the same procedure you used in this experiment. 2 A1(s)+2 KOH(aq) + 4 H2SO4(aq) +22 H200) 2 KAI(SO4)2 12H20(s) +3 H2(g) How many moles of Al did the student use in this experiment? a. How many moles of the Alum, KAI(SO42 * 12 H20, Use the coefficients from the balanced chemical equation.) b. can be produced theoretically? (Hint- What is the mass of Alum theoretically possible? (Hint - Use the molar mass of the alum calculated in question #1.) c. d. If the student's crystals had a mass of 32.105 g, what is the percent yield?

CHEMWORK With the advent of techniques such as scanning tunneling microscopy, it is now possible to "write" with individual atoms by manipulating and arranging atoms on an atomic surface. a. If an image is prepared by manipulating iron atoms and their total mass is 1.30 x 10-20 g, what number of iron atoms were used? 1 mole = 6.022 x 1023 atoms Fe atoms b. If the image is prepared on a platinum surface that is exactly 22 platinum atoms high and 13 platinum atoms wide, wha is the mass (grams) of the atomic surface? g Pt c. If the atomic surface were changed to ruthenium atoms and the same surface mass as determined in part b is used, what number of ruthenium atoms is needed to construct the surface? Ru atoms

6. Which of the following has more atoms? A. 1.10 g of hydrogen (H) atoms B. 14.7 g of chromium (Cr) atoms Write the letter of your choice and support your answer with computations. No solution, no credit. 7. Calculate the number of C, H and O atoms in 1.50 g of glucose, C6H12O6. There should be 3 answers.

Consider the following: 4NH3 + 5O2 → 4NO + 6H2O In an experiment, 5.42 g of NH3 are allowed to react with 7.26 g of O2. How many grams of NO are formed?

Chemistry An element consists of 4.35% of an isotope with mass 49.946 u, 83.79% of an isotope with mass 51.9405 u, 9.50% of an isotope with mass 52.9406 u, and 2.36% of an isotope with mass 53.9389 u. Calculate the average atomic mass, and identify the element. Average atomic mass = u Element:

You need to convert the copper in 0.2000 g of CuSO4 5 H2O (249.55 g/mol) to Cu(IO3)2 using KIO3.   1. How many moles of Cu2+ are in CuSO4 5 H2O?       2. From your answer in a, how many moles of IO3- are present?       3. From your answer in b, what is the mass of KIO3 (214 g/mol) is needed?

How many sodium ions are present in 20.0 mL of 0.10 M Na2S

Balance the equation below, which uses imaginary elements (they still follow the usual convention – each element symbol is one or two letters long, beginning with a capital letter). Bf2X2Ki3 + L2 → Bf2X4Ki6 + BfL

The formula of glucose is Ce Hi12O6. a. The number of molecules in 166 grams of glucose would be less than Avogadro's number. b. What is the mass in grams of 1 glucose molecule? grams

The reaction of Cr₂O3 with silicon metal at high temperatures will make chromium metal. 2Cr₂O₂ (s) + 3Si(s) 4Cr(1) + 3SiO₂ (s) The reaction is begun with 167.00 g of Si and 124.00 g of Cr₂O3.