What type of ionic compound is CO3?

What is the molar mass of a gas that has density of 2.054 g/l

Draw the lewis dot structure for each of the following polyatomic ions

Which is the solubility product expression for caf2(s)?  [ca2+]/[f–]2  [ca2+][f2–]  [ca]+[f]2  [ca2+][f–]2