January 2014 Chemistry Regents #66-70

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Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50

Questions 51-54 Questions 55-57 Questions 58-61 Questions 62-63 Questions 64-65 Questions 66-70

Questions 71-75 Questions 76-77 Questions 78-81 Questions 82-85

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Questions

 

  Base your answers to questions 66 through 70 on the information below.

Baking soda, NaHCO3, can be commercially produced during a series of chemical reactions called the Solvay process. In this process, NH3(aq), NaCl(aq), and other chemicals are used to produce NaHCO3(s) and NH4Cl(aq). To reduce production costs, NH3(aq) is recovered from NH4Cl(aq) through a different series of reactions. This series of reactions can be summarized by the overall reaction represented by the unbalanced equation below.

66 Write a chemical name for baking soda. [1]
Answer==>  sodium hydrogen carbonate


67 Determine the percent composition by mass of carbon in baking soda (gram-formula mass 84 grams per mole). [1]
Answer==>  14%


68 State the color of bromcresol green in a sample of NH3(aq). [1]
Answer==>  Blue


69 Determine the mass of NH4Cl that must be dissolved in 100. grams of H2O to produce a saturated solution at 70.°C. [1]
Answer==>  61g, 62g or 63g


70 Balance the equation in your answer booklet for the overall reaction used to recover NH3(aq), using the smallest whole-number coefficients. [1]

 
Answer==>  2 NH4Cl + CaO --> 2NH3 + H2O + CaCl2

 on to Questions 71-75

 

 
 

Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50

Questions 51-54 Questions 55-57 Questions 58-61 Questions 62-63 Questions 64-65 Questions 66-70

Questions 71-75 Questions 76-77 Questions 78-81 Questions 82-85

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