Two, extra TOPIC 4 questions for my AP classes

September 29, 2008
Tags:
Categories: AP | AP TOPIC 04

Take a look at these BEFORE the test on Wed 10/1.

Question 1: It concerns silicon tetrachloride and can be found as part (b) on this page; http://www.drbateman.net/asa2sums/sum1.2/test1.2.htm

A few notes about this question;

  • 1cm3 = 1mL
  • 1dm3 = 1L
  • the equation for “neutralisation” that the questions refers to is;

HCl + NaOH ==> NaCl + H2O

  • The correct answer is 91.8%

Question 2: This question has been adapted from an unkown source;

2.00 g of an impure copper ore that contains some undetermined amount of copper pyrites with the formula CuFeS2, is treated so that all of the copper ions are dissolved into exactly 100mL of solution. 20mL portions of this solution are treatd with excess KI and the reaction below takes place;

2Cu2+ + 4I ==> 2CuI + I2

The iodine that is produced in this reaction requires 18.3mL of 0.10M sodium thiosulfate to react completely according to the equation below;

2S2O32- + I2 ==> S4O62- + 2I

Calculate the % purity of the ore.

  • The correct answer is 84%

 

 

0 Comments

Submit a Comment

Your email address will not be published. Required fields are marked *

HONORS MATERIALS

REGULAR MATERIALS

ORGANIC COURSE 2

ADRIAN

Read about Adrian as an Educator of over thirty years, as a Chemistry Tutor with a resume of helping hundreds of private clients over three decades, and as an Author and Writer with an extensive portfolio of work

ADRIAN'S CORE VALUES

Read about the the four Core Values that drive all of Adrian's professional endeavors, and that act as the cornerstones of his work

ADRIAN'S CHEMISTRY BOOKS

Check out all of my books

CHEMISTRY BOOK GALLERIES

Pretty pictures of my books

CHEMISTRY WRITING PORTFOLIO

Chemistry writing beyond books