An independent variable Is the variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable, In that case - 1. sulfate solution, 2. potassium iodide solution, 3. hydrochloric acid solution.
You kind of need to show more, but the independent variable would be something that you are changing to then measure the reaction, like the time left in for example.
A cooked chicken would be somewhat burnt or cooked. A glass of kool aid would be mixed, or aka homogenous mixture. The glass would maintain a color, because its not water.
