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Your email address will not be published.

HONORS MATERIALS

REGULAR MATERIALS

ORGANIC COURSE 2

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

PAYPAL
QUICKPAY

Send any $ amount via PayPal Quick Pay

CREDIT CARDS
VIA STRIPE

Send any $ amount with Visa, MC, Amex etc.

VENMO
TRANSFER

Send any $ amount via Venmo transfer

SUBMIT A
SCHOOL PO

Pay via an invoice and a school purchase order