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