Is 2HCl soluble in water?

Is BaSO4 soluble in water?

HCl, strictly speaking, is a gas. However, it is VERY soluble in water, and the stuff used in laboratories is about 37% HCl.

BaSO4 is quite insoluble in water. Here is a simplified link for solubility.
http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html