1. In the olden days, US minted pennies were pure copper, but copper got so expensive that a pure copper penny was worth more than 1 cent. Modern pennies are composed of zinc and coated with student determines the mass of a penny to be 2.482 g. After making several scratches in a penny, the student puts the penny into hydrochloric acid, where the zinc (but not the copper) reacts with hydrochloric acid via a single replacement reaction. The hydrogen is collected at 25°C over water. The collected gas occupies 0.899L at a total pressure of 791 mm Hg. copper. A. Calculate the moles of hydrogen produced in the reaction. (Hint: Use the Table 1. to determine the vapor pressure of water and assume that all of the zinc in the penny dissolves.) B. Write a balanced chemical reaction for zinc and hydrochloric acid. C. Use stoichiometry to calculate the mass of zinc in the penny. D.Determine the percent zinc (by mass) in the penny.

1. In the olden days, US minted pennies were pure copper, but copper got so expensive that a pure copper penny was worth more than 1 cent. Modern pennies are composed of zinc and coated with student determines the mass of a penny to be 2.482 g. After making several scratches in a penny, the student puts the penny into hydrochloric acid, where the zinc (but not the copper) reacts with hydrochloric acid via a single replacement reaction. The hydrogen is collected at 25°C over water. The collected gas occupies 0.899L at a total pressure of 791 mm Hg. copper. A. Calculate the moles of hydrogen produced in the reaction. (Hint: Use the Table 1. to determine the vapor pressure of water and assume that all of the zinc in the penny dissolves.) B. Write a balanced chemical reaction for zinc and hydrochloric acid. C. Use stoichiometry to calculate the mass of zinc in the penny. D.Determine the percent zinc (by mass) in the penny.

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

See similar textbooks

Similar questions

Pennies that are currently being minted are composed of zinc coated with copper. A student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coating (to expose the underlying zinc). The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the HCl (the copper remains undissolved): Zn(s) + 2 HCl(aq) --------> H2(g) + ZnCl2(aq)The student collects the hydrogen produced over water at 25°C. The collected gas occupies a volume of 0.899 L at a total pressure of 791 mmHg. Calculate the percent zinc (by mass) in the penny. (Assume that all the Zn in the penny dissolves.)
One way the U.S. Environmental Protection Agency (EPA) tests for chloride contaminants in water is by titrating a sample of silver nitrate, solution. Any chloride anions in solution will combine with the silver cations to produce bright white silver chloride precipitate. Suppose an EPA chemist tests a 200. mL sample of groundwater known to be contaminated with cadmium chloride, which would react with silver nitrate solution like this: CdCl2(aq) + 2 AgNO3(aq) → 2 AgCl(s) + Cd (NO3)2(aq) The chemist adds 89.0 mM silver nitrate solution to the sample until silver chloride stops forming. He then washes, dries, and weighs the precipitate. He finds he has collected 5.4 mg of silver chloride. Calculate the concentration of cadmium chloride contaminant in the original groundwater sample. Be sure your answer has the correct number of significant digits. E d OL E
One way the U.S. Environmental Protection Agency (EPA) tests for chloride contaminants in water is by titrating a sample of silver nitrate solution. Any chloride anions in solution will combine with the silver cations to produce bright white silver chloride precipitate.Suppose an EPA chemist tests a 250.mL sample of groundwater known to be contaminated with cadmium chloride, which would react with silver nitrate solution like this: CdCl2(aq)+2AgNO3(aq)→2AgCl(s)+CdNO32(aq). The chemist adds 51.0mM silver nitrate solution to the sample until silver chloride stops forming. She then washes, dries, and weighs the precipitate. She finds she has collected 8.9mg of silver chloride. Calculate the concentration of cadmium chloride contaminant in the original groundwater sample. Be sure your answer has the correct number of significant digits.
One way the U.S. Environmental Protection Agency (EPA) tests for chloride contaminants in water is by titrating a sample of silver nitrate solution. Any chloride anions in solution will combine with the silver cations to produce bright white silver chloride precipitate. Suppose an EPA chemist tests a 250. mL sample of groundwater known to be contaminated with copper(II) chloride, which would react with silver nitrate solution like this: CuCl,(aq) + 2 AgNO3(aq) → 2 AgCl(s) + Cu(NO,),(aq) The chemist adds 68.0 mM silver nitrate solution to the sample until silver chloride stops forming. He then washes, dries, and weighs the precipitate. He finds he has collected 4.3 mg of silver chloride. Calculate the concentration of copper(II) chloride contaminant in the original groundwater sample. Be sure your answer has the correct number of significant digits. mg x10
Your crucible has a mass of 30.252 g when empty, and does not change upon heating. You add some solid iron and then weigh the crucible and iron to be 32.925 g together. You then burn the iron in the presence of oxygen following the procedure in the handout. Assume that there are no contaminates and all of the iron is converted to iron oxide. The final mass of the crucible and iron oxide is 33.976 g, which does not change upon heating. The unrounded empirical formula obtained from these measurements would be FeOX, where X is a decimal type number (not necessarily a whole number). Give the value of X in the blank below in decimal format with the correct number of significant figures.
9
A student does an experiment to determine where titanium metal should be placed on the activity series chart. He places newly cleaned pieces of titanium into solutions of nickel(II) nitrate, lead(11) nitrate, and magnesium nitrate. He finds that the titanium reacts with the nickel(II) nitrate and lead(11) nitrate solutions, but not with the magnesium nitrate solution. From this information, place titanium in the activity series in a position relative to these ions.
One reactant goes into iridium, how many products come out? What did you see when you were watching the reaction occur? What evidence in the equation matches the observation? Are the products examples of atoms, elements, or compounds? What happened to the iridium catalyst during the change? The product words read “nitrogen and hydrogen gas”. The equations tells us the state of matter, too. What evidence in the equation tells us the state of matter What state of matter is the hydrazine reactant?
Here is some information to help. In this experiment, magnesium metal is heated until it reacts with oxygen in the air according to the following balanced equation: 2Mg(s)+ O2(g) → 2MgO(s) (silver metal) (white-gray ash) As the magnesium burns in air, it may also combine with nitrogen in air. To remove any nitride product, water is added, and the product is reheated. Any nitride product is converted to magnesium oxide and ammonia. 3Mg(s)+ N2(g) → Mg3N2(s) Mg3N2(s)+3H2O(l)→3MgO(s)+2NH3(aq) A weighed amount of the magnesium metal is used, and the mass of the oxide product formed is determined at the end of the experiment. The mass of oxygen that combines with the magnesium is obtained from the difference between the mass of the oxide product and the original mass of magnesium. mass of oxide product-mass of magnesium=mass of oxygen in oxide product The empirical formula of the oxide…
Write a balanced chemical equation for each of the following. Express your answer as a chemical equation. Identify all of the phases in your answer. a. Solid lead(II) sulfide reacts with aqueous hydrochloric acid to form solid lead(II) chloride and dihydrogen sulfide gas. b. Gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane (CH4) and liquid water. c.Solid iron(III) oxide reacts with hydrogen gas to form solid iron and liquid water. d.Gaseous ammonia (NH3) reacts with gaseous oxygen to form gaseous nitrogen monoxide and gaseous water.
One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(II) carbonate, in concentrated sulfuric acid. The sulfuric acid reacts with the copper(II) carbonate to produce a blue solution of copper(II) sulfate. Scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction: Fe(s) + CuSO (aq) → Cu(s) + FESO,(aq) Suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. He adds powdered iron to a 200. mL copper(II) sulfate sample from the plant until no more copper will precipitate. He then washes, dries, and weighs the precipitate, and finds that it has a mass of 64. mg. Ar Calculate the original concentration of copper(II) sulfate in the sample. Round your answer to 2 significant digits. 10
Your crucible has a mass of 30.074 g when empty, and does not change upon heating. You add some solid iron and then weigh the crucible and iron to be 32.860 g together. You then burn the iron in the presence of oxygen following the procedure in the handout. Assume that there are no contaminates and all of the iron is converted to iron oxide. The final mass of the crucible and iron oxide is 33.961 g, which does not change upon heating. The unrounded empirical formula obtained from these measurements would be FeOX, where X is a decimal type number (not necessarily a whole number). Give the value of X in the blank below in decimal format with the correct number of significant figures.Answer: ________