. A closed bottle containing water at 30°C is carried to
the moon in a spaceship. If it is placed on the surface
of moon, what will happen to the water as soon as
the lid is opened ?
(a) The water will freeze
(b) The water will boil
(c) It will decompose into H, or O,
(d) Nothing will happen to it
Answers
a.........
Hope you get your answer
For most practical purposes, Moon is considered to be surrounded by vacuum. In a vacuum the freezing and boiling point of water are the same. As soon as you will open the bottle, water will find itself in a vacuum and the surface area of the water will immediately start to boil due to lack of surrounding air pressure. But there is no heat here, so the water doesn't get any hotter. As water turns into gas it occupies more volume, but contains the same amount of heat. Same heat in a larger area causes cooling. Here cooling is rapid i.e. water reaches its freezing temperature before it boils completely, turning it into ice, but because boiling was taking place along with freezing, the ice will be in the form of mist (mist: when warmer water in air rapidly cools). Over time, this mist will sublimate due to falling sunlight.
But
The side of the moon in which you have opened the bottle will also play a role. If you open the bottle at the side of the moon facing sunlight, the amount of water that evaporates away before freezing will be high as the temperature in the sunny side is close to 125 degree Celsius. Similarly, if you open the bottle at the darker side of the moon where temperature is close to minus 150 degree Celsius, the freezing will be almost instantaneous.
Hope this helps to understand.