June 2014 Chemistry Regents #36-40

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

Question 51-54 Questions 55-56 Questions 57-58 Questions 59-61 Questions 62-65 Questions 66-69 Questions 70-72 Questions 73-75  Questions 76-79  Questions 80-82  Questions 83-85

Other Regents Exams

 

Questions

Answer Links

Explanations

36 Which reaction is single replacement?

(1) 2H2O2 --> 2H2O + O2

(2) 2H2 + O2 --> 2H2O

(3) H2SO4 + Mg --> H2 + MgSO4

(4) HCl + KOH --> KCl + H2O

3 link an element replaces another element in a compound

Choice  #4 is the answer to #77

37 The accepted value for the percent by mass of water in a hydrate is 36.0%. In a laboratory activity, a student determined the percent by mass of water in the hydrate to be 37.8%. What is the percent error for the student's measured value?

(1) 5.0%    (3) 1.8%

(2) 4.8%     (4) 0.05%

1   equation is on the back page, plug in numbers

((37.8-36.0)/36.0)  x 100%

38 The boiling points, at standard pressure, of four compounds are given in the table below.
Compound Boiling Point (oC)
H2O 100.0
H2S -59.6
H2Se -41.3
H2Te -2.0

What type of attraction can be used to explain the unusually high boiling point of H2O?

(1) ionic bonding

(2) hydrogen bonding

(3) polar covalent bonding

(4)  nonpolar covalent bonding

2 link H-bonding question

look for

H with F O or N

 

39 Which formula represents a molecule with the most polar bond?

(1) CO    (3) HI

(2) NO    (4) HCl

 

4 link largest difference in electronegativity is the most polar

see table S of electronegativity values

 

40  The graph below represents the uniform heating or a substance from the solid to the gas phase.

Which line segment of the graph represents boiling?

(1) AB    (3)  CD

(2) BC    (4)  DE

4 link the upper plateau is boiling

 

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

Question 51-54 Questions 55-56 Questions 57-58 Questions 59-61 Questions 62-65 Questions 66-69 Questions 70-72 Questions 73-75  Questions 76-79  Questions 80-82  Questions 83-85

Back to Regents Exams