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Howard University General Chemistry Lab. I spring 2021- Quiz 4 (Limiting reagent) Name: Bryce Augustine

ID: 02987204

Q1. Which of the following statements is FALSE for the chemical equation given below in which nitrogen gas reacts with hydrogen gas to form ammonia gas assuming the reaction goes to completion? N2 + 3H2 2NH3 a. The reaction of one mole of H2 will produce 2/3 moles of NH3. b. One mole of N2 will produce two moles of NH3. c. One molecule of nitrogen requires three molecules of hydrogen for complete reaction. d. The reaction of 14 g of nitrogen produces 17 g of ammonia. e. The reaction of three moles of hydrogen gas will produce 17 g of ammonia. Q2. Which compound is the limiting reagent in this chemical reaction? Na2CO3 + CaCl2 → CaCO3 + 2NaCl CaCl2 Q3. Consider respiration, one of the most common chemical reactions on earth. C6H12O6+6O2→6CO2+6H2O+energy What mass of carbon dioxide forms in the reaction of 25 grams of glucose with 40 grams of oxygen? 25 g (1 mol/180.06g) = 0.1388 mol C6H12O6 40 g ( 1 mol/32.0g) = 1.25 mol O2 1.25 mol O2 (1 mol/ 6 mol) = .208 mol C6H12O6 .1388 mol C6H12O6 (6 mol/ 1 mol) = .8328 mol O2 Ratio is 4.004 .1388 (6/1) = .8328 mol CO2 Q4. How much the excess reagent remains if 24.5 grams of CoO is reacted with 2.58 grams of O 2? 4CoO+O2→2Co2O3 24.5g (1mol/74.9g) = .327 mol CoO 2.58 g (1 mol/32g) = .0806 mol O2 .0806(4/1) = .3224 .327-.3223 = .0046 mol of excess reagent

Q5. The limiting reagent in a chemical reaction is one that: a. has the largest molar mass (formula weight). b. has the smallest molar mass (formula weight). c. has the smallest coefficient. d. is consumed completely. e. is in excess. Q6. If 5.0 g of each reactant were used for the the following process, the limiting reactant would be: 2KMnO4 +5Hg2Cl2 + 16HCl (a) KMnO4 (b) HCl (c) H2O (d) Hg2Cl2 (e) HgCl2

10HgCl2 + 2MnCl2 + 2KCl + 8H2O...