Thursday, September 10th

Only homework is to read the Background and Pre-Lab sections of the Double Replacement / Ionic Reactions Lab. Please complete the one question in the Pre-Lab section. Also, within the Background section is a discussion on the concept of Ksp (Solubility Product). Ksp is the rating of how soluble a compound is. Any value that is less than 1 will not be soluble in water for our purposes. Thus, if you cannot determine if a compound is soluble, look at table A5.4 (on page A25 in the back of the book). Example: In class there was a debate on the solubility of lead (II) chromate (PbCrO4). Chromate is not included on the sheet of general solubility rules that was supplied to you. Another way to determine its solubility is to look up the Ksp value for lead (II) chromate. The Ksp value for PbCrO4 is 2 x 10^-16. This value is far less than one, thus the compound will not dissolve in water. We will explore the true use and meaning of Ksp next spring.