August 2009 Chemistry Regents #56-58

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Questions

Base your answers to questions 56 through 58 on the information below.

 

A 1.0-gram strip of zinc is reacted with hydrochloric acid in a test tube. The unbalanced equation below represents the reaction.

Zn(s) + HCl(aq) ==>H2(g) + ZnCl2(aq)

56 Balance the equation in your answer booklet for the reaction of zinc and hydrochloric acid, using the smallest whole-number coefficients. [1]

 ________ Zn(s) + ________ HCl(aq) ==>________ H2(g) + ________ ZnCl2(aq)

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•  Zn(s) + 2 HCl(aq) ==> H2(g) + ZnCl2(aq)

57 Explain, using information from Reference Table F, why the symbol (aq) is used to describe the product ZnCl2. [1]

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The product ZnCl2 is soluble in water.

(Table F is a solubility table, the answer is either soluble or insoluble if you are using it)

58 Explain, in terms of collision theory, why using 1.0 gram of powdered zinc, instead of the 1.0-gram strip of zinc, would have increased the rate of the reaction. [1]

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Answer==>MORE EFFECTIVE COLLISIONS

The greater surface area in powdered zinc would have resulted in more frequent collisions between the zinc atoms and the hydrogen ions in the HCl(aq).

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Questions 51-55 Questions56-58 Questions 59-63 Question 64 Questions 65-67 Questions 68-72 Questions 73-76 Questions 77-79 Questions 80-81

 
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