A solution which on treatment with hydrochloric acid produces a colourless, odourless gas which turns lime water milky is most likely to be a
Answer Details
The given information tells us that the solution produces a colorless and odorless gas, which turns lime water milky on reaction with hydrochloric acid. This indicates that the gas produced is carbon dioxide (CO2). The only option that contains carbonate ion (CO32-) which produces CO2 on reaction with hydrochloric acid is "trioxocarbonate (IV)" or "carbonate". Hence, the solution is most likely to be a "trioxocarbonate (IV)" or "carbonate" solution.