January 2010 Chemistry Regents #69-71

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Questions

Base your answers to questions 69 through 71 on the information below.

In a laboratory investigation, magnesium reacts with hydrochloric acid to produce hydrogen gas and magnesium chloride. This reaction is represented by the unbalanced equation below.

Mg(s) + HCl(aq) ==>H2(g) + MgCl2(aq)

69 State, in terms of the relative activity of elements, why this reaction is spontaneous. [1]

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Magnesium is more active than hydrogen.

H2 is less active than Mg.

(Use Table J)

70 Balance the equation in your answer booklet, using the smallest whole-number coefficients. [1]

_____ Mg(s) + _____ HCl(aq) ==>_____ H2(g) + _____ MgCl2(aq)

HIGHLIGHT TO SEE THE ANSWER

Mg(s) +  2   HCl(aq) ==>H2(g) + MgCl2(aq)

71 Write a balanced half-reaction equation for the oxidation that occurs. [1]

HIGHLIGHT TO SEE THE ANSWER

Mg ==>Mg2+ + 2e-

charge goes up electrons go on the more positive side

On to Questions 72-75

 

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

Questions 51-52 Questions 53-55 Questions 56-57 Questions 58-60 Questions 61-63 Questions 64-65 Questions 66-68 Questions 69-71 Questions 72-75 Questions 76-78 Questions 79-81  Questions 82-84

 
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