Wednesday
October 22, 2014

Homework Help: chemistry

Posted by cbarnett on Monday, December 4, 2006 at 9:40am.

I have two Questions I need help with.

1. Why do some combinations of ionic compounds form a precipitate while other ionic compounds don't?
AND
2. Solutions of lead(II)nitrate and potassium iodide are combined in a test tube and form a yellow precipitate. What is the molecular equation for this reaction?

Well, a look around my pasture tells me that most ionic substances are not soluble. I have a lot of limestone here. Some are soluble, notably, Alkaline metals , and nitrates.
Solubility has to do with energy. These ions are attracted to water ions, or water polar ends, and when in the vicinity, release energy. If that energy is greater than the energy binding the ionic compound, then the compound breaks apart and dissolves as ions. If not, it is a precipitate.

Lead(II) iodide is an example of the internal binding energy being greater than the hydration energy.

Pb(NO3)2(aq) + KI(aq) ==> PbI2(s) + KNO3(aq)

You balance

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Chemistry - why do some combinations of ionic compounds form a precipitation ...
chemistry - Which of the following statements concerning differences between ...
Chemistry - Explain why the melting points of ionic compounds and molecular ...
chemistry - What are the certain conditions when ionic compounds conduct an ...
CHEMISTRY - list three differences between molecular and ionic compounds, and ...
Chemistry - For each of the following, write a net ionic equation (modeled ...
Science URGENT!!! - Mulitple choice: why is it uncommon to draw lewis diagrams ...
Chemistry (Inorganic) - Given the two substances Sodium Nitrate (NaNO3) and Urea...
SCIENCE - 1. Multiple choice: why is it uncommon to draw lewis diagrams for ...
CHEMISTRY.. - 1. Will a precipitate form if solutions of potassium sulfate and ...

Search
Members