June 2019 Chemistry Regents #66-69

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Question 66-69

 

 

Base your answers to questions 66-69

During a laboratory activity, appropriate safety equipment was used and safety procedures were followed. A laboratory technician heated a sample of solid KClO3 in a crucible to determine the percent composition by mass of oxygen in the compound.  The unbalanced equation and the data for the decomposition of solid KClO3 are shown below.

 

66.Write the chemical name for the compound that decomposes.

Answer--> potassium chlorate

67. Based on the lab data, show a numerical setup to determine the number of moles of O2 produced.  Use 32g/mol as the gram-formula mass of O2.

Answer--> 0.8/32    just the setup

68.  Based on the lab data, determine the mass of KCl produced in the reaction.

Answer-->1.27g  ....... (2.07-0.80)

69. Balance the equation in the answerbook.

Answer-->   2KClO3  -->  2 KCl  +  3 O2

F halides

see Table F halides

on to Questions 70-73

 

 

Questions 1-5 Questions 6-10 Questions 11-15 Questions 16-20 Questions 21-25 Questions 26-30 Questions 31-35 Questions 36-40 Questions 41-45 Questions 46-50

Questions 51 Questions 52-54 Questions 55-57 Questions 58-61 Questions 62-65 Questions 66-69 Questions 70-73 Questions 74-77 Questions 78-80 Questions 81-85  

 

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