This simulation leads you through a step-by-step procedure to construct an x-y diagram for a trayed absorption column that is used to remove an impurity from a gas feed by absorbing the impurity in a liquid solvent. The number of trays/stages needed to obtain an outlet concentration of y₁ ppm in the gas stream is calculated. Click the “new problem” button to create a different set of conditions and reset the simulation. Click “next” to go to the next step. Check “hint” for a hint, and check “solution” to see the solution before selecting the next step. Once “solution” is checked, your answer cannot be changed, and once “next” is selected, you cannot go back. To restart, press “new problem”. For steps 2 and 3, check “show column” to display a diagram of the absorption column.