Can water go "Bad"? Rain water

I collected rain water last night in a bowl (For my Carnivorous plants) and it has been in my draw with cling film on it for a day.

Will it go bad?

apparently, according to rsearchers in metaphysics, the structure of water can actually change slightly when exposed to various radiations and conditions. Such changes would include a slight change for example in the angle formed by the two hydrogen atoms and the oxygen atom. It is still water of course but now it has slightly modified characteristics and is not quite the same. For example plants much prefer water which has been exposed to the air and sunlight. ... better still if it is taken directly from a natural stream or as fresh rainwater. Any water which has been exposed to an artificial process such as distillation loses some quality.
With this in mind then it is likely that the water in your drawer will lose some property which is essential to the plant's happiness. This is even more true if it has been covered by some artificial substance like Saran Wrap. What happens is that the evaporated water in the space above the water surface will condense on the wrap and and drip back into the main body of water carrying with some essence of the wrap substance and itself being modified again. This process may not be visible in such limited venues, however it still occurs on a microscopic level.
Tap water is not so great since it has been stored for some time without sunlight and likewise has been in contact with metal or plastic, etc..... not good !
I recommend you to an excellent book called ''the secret life of plants'' by Tompkins.

well, no, not in the way that food goes bad. if you leave it in a plastic or metal container for a long time, it gets warm and takes on a taste of the container, making it taste a bit crappy, but it won't kill you or make you sick. Water can get infested by bacteria or other growth that probably isn't the best stuff to consume if the water sits around stagnant for a long time like in a puddle, but water for watering your plants won't go bad for that purpose even if it starts its own little colony of algae; the plants can handle it.

If you add salts or something to the water, it can be bad for plants even if it wouldn't be bad for you. Pouring soda pop or koolaid onto plants isn't all that great a thing to do.

But water in a bucket is just fine for plants even if it has been in the bucket for days.

Yes in the sense that dissolved oxygen levels fall over time which increases the growth of algae and bacteria. Also chemiclas can leach into water stored for long periods from the container it is stored in.

if you are using it for plants i doubt it will matter where the water came from, but water doesn't go bad.

it will be fine. plants don't like water which is too cold so it might be better now than in was.