Solubility Lab

Solubility Lab

Class on October 31 (Halloween)

Written by: Jordan C.

After the class had a short discussion of Shakespearean iambic pentameter, we got down to business.

Remember that soluble means that the ionic bond is weaker than the water bond and therefore remains separated.

Going over the double replacement reactions and solubility lab:

• Pre-lab Questions: The class did not go over these because they were not assigned.
• Data: The data did not have to corrected because the rules as to the solubility and insolubility with cations and anions is more important. 
• Post-lab Questions: Ms. Friedmann gave an example of each of the questions and demonstrated how to find the answer to any of the class's requests. 

Question 1:

• Although the 2 possibilities for the possible precipitate were required, Ms. Friedmann saw this as an opportunity to demonstrate a balanced molecular equation for:

Combination of: Ba(NO3)2 and Na2SO4. 

Ba(NO3)2(aq) + Na2SO4(aq) ---> BaSO4(s) + 2 NaNO3(aq)

Ba(NO3)2(aq) + Na2SO4(aq) ---> BaSO4(aq) + 2 NaNO3(s)

Question 2: 

• The demonstration included the combination of Ba(NO3)2 + Na2CO3. She also showed the net ionic and ionic equations for practice. 

Molecular: 

Ba(NO3)2(aq) + Na2SO4(aq) ---> BaSO4(s) + 2 NaNO3(aq)

Complete ionic:

Ba^+2(aq) + 2 NO3^-(aq) + 2 Na+(aq) + SO4^-2(aq) --->BaSO4(s) + 2 Na^+2(aq) + 2 NO3

Net ionic:

Ba^+2(aq) + SO4^-2(aq) ---> BaSO4(s)

Question 3:

a) SO4^-2, halides (ions of halogens ) Cl^-, I^-

b) silver cations Ag^+1 and barium cations Ba^+2

Question 4: 

a) CO3^-2 carbonates, OH^- hydroxides, PO4^-3 phosphates

b) potassium cations K^+, sodium ions Na^+1 (THESE ARE ALKALI METAL IONS)

Question 5:

a) Bromine salts would be soluble because it is in the halogen family, and therefore is closely related with the other soluble halogens.

Question 6:

This is one of the most important aspects of the lab. All the information leads up to discovering the rules of solubility with cations and anions. 

Ionic Compounds:

• Carbonates: insoluble except alkali metals (sodium, potassium)
• Halides: soluble except silver
• Hydroxides: insoluble except alkali cations (K^+1)
• Nitrates: soluble except none :)
• Phosphates: insoluble except alkali cations
• Sulfates: soluble except barium (Ba^+2)
• Alkali Metal salts: soluble except none :)
• Ammonium salts: soluble except none :)

As class came to a close, we had the opportunity to make bubbles and bounce them off gloves. It was suuuuper fun. 

Thursday, 10/31 Homework

1) Complete the "Solubility Rules and Practice" worksheet (in the Unit 4 Handouts folder).  Due tomorrow.

2) WebAssign 4.2 -- Precipitation Reactions.  Due Sunday night, 11/3, 11:59 pm.

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