Problem: You are presented with a white solid and told that due to careless labeling it is not clear if the substance is barium chloride, lead chloride, or zinc chloride. When you transfer the solid to a beaker and add water, the solid dissolves to give a clear solution. Next a Na2SO4(aq) solution is added and a white precipitate forms.What is the identity of the unknown white solid?

🤓 Based on our data, we think this question is relevant for Professor Hendrickson's class at UCB.

FREE Expert Solution

Na2SO4(aq)

▪ sodium → group 1A → +1 charge → Na+
 ▪ sulfate → polyatomic ion → -2 charge → SO4–


• group 1A ions are soluble with everything → Na+ will not precipitate

• find a cation (positively charged ion) that is insoluble with SO42–

▪ Sulfates (SO42-) are soluble except those of Ca2+, Sr2+, Ba2+, Ag+, and Pb2+

View Complete Written Solution
Problem Details

You are presented with a white solid and told that due to careless labeling it is not clear if the substance is barium chloride, lead chloride, or zinc chloride. When you transfer the solid to a beaker and add water, the solid dissolves to give a clear solution. Next a Na2SO4(aq) solution is added and a white precipitate forms.

The figure shows three beakers with a solid in the first beaker, with a solution in the second beaker, and with a solution with a precipitate in the third one. There is a right arrow labeled as add H2O between the first and the second beakers. There is a right arrow labeled as add aqueous Na2SO4 between the second and the third beakers.


What is the identity of the unknown white solid?

Learn this topic by watchingSolubility Rules Concept Videos
All Chemistry Practice Problems Solubility Rules Practice Problems
Q.As K2O dissolves in water, the oxide ion reacts with water molecules to form hydroxide ions.Enter the molecular equation for this reaction.
Q.The accompanying photo shows the reaction between a solution of Cd(NO3)2 and one of Na2S. What is the identity of the precipitate?
Q.Three solutions are mixed together to form a single solution; in the final solution, there are 0.2 mol Pb(CH3COO)2, 0.1 mol Na2S, and 0.1 mol CaCl2 pr...
Q.You know that an unlabeled bottle contains an aqueous solution of one of the following: AgNO3, CaCl2, or Al2(SO4)3. A friend suggests that you test a ...
See all problems in Solubility Rules