I was supposed to figure out whether the following equations produced precipitates or not. Here are my answers, but I know that they are wrong. So I still can't figure out where I'm messing up...? Please help!

Question

HgCl2 (aq) + K2CrO4 (aq) = Yes
Ba(OH)2 (aq) + NaClO3 (aq) = No
ZnI2 (aq) + CaSO4 (aq) = No
SnCl2 (aq) + MgBr2 (aq) = Yes

Answer 1

1 is ok.
2 is ok.
3 is ok.
4 should be no. Of the possible combinations, SnBr2 is soluble as is MgCl2. Did you use the chart I posted for you? It doesn't list mercury(II) chromate but questions 1, 2, and 3 are covered by the table. To be honest about it I can't find the mercury chromate info anywhere; however, mercury(II) dichromate is highly insoluble and my best educated guess is that mercury(II) chromate is insoluble as well. So you're batting 3 out of 4 which isn't bad at all.

Answer 2

Great, thanks! :)