If a donkey's feces touches a cardboard box, and then the box is placed on a bed or a chair, does it render the place it was put on impure?

If wet donkey droppings touch cardboard or anything similar, the contaminated spot becomes impure. If this wet, impure spot is then placed on a wet chair or bed, the impurity transfers to them. However, if the donkey droppings were dry at the time of contact, no impurity is transferred.

The prayers performed by the questioner in an impure place, while she was ignorant of or forgot about the impurity, are valid and do not need to be repeated. Similarly, if she was ignorant of the rulings of impurity, some scholars deem her prayer valid. However, if she was ignorant of the invalidity of prayer in an impure place, her prayer is invalid and she must make it up, because this matter is well-known, and ignorance of it is not excused.