June 2018 Chemistry Regents #66-69

Highlight to reveal answers and explanations

 

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 51-53 Questions 54-56 Questions 57-59 Questions 60-62 Questions 63-65 Questions 66-69 Questions 70-73 Questions 74-76  Questions 77-79  Questions 80-82  Questions 83-85 

 

Other Regents Exams

Question 66-69

 

 

Base your answers to questions 66 through 69 on the information below and on your knowledge of chemistry.  

In the late 1800s, Dmitri Mendeleev developed a periodic table of the elements known at that time. Based on the pattern in his periodic table, he was able to predict properties of some elements that had not yet been discovered. Information about two of these elements is shown in the table below.

66 Identify the phase of Ea at 310. K. [1]

Answer--> liquid

67 Write a chemical formula for the compound formed between Ea and Cl. [1]

Answer-->EaCl3 or GaCl3

68 Identify the element that Mendeleev called eka-silicon, Es. [1]

Answer-->Ge or Germanium

69 Show a numerical setup for calculating the percent error of Mendeleev’s predicted density of Es. [1]

Answer-->((5.5-5.3)/5.3)  *100%

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 51-53 Questions 54-56 Questions 57-59 Questions 60-62 Questions 63-65 Questions 66-69 Questions 70-73 Questions 74-76  Questions 77-79  Questions 80-82  Questions 83-85 

 

Back to Regents Exams