Akno3 solution containing 47 g of kno3 per 100.0 g of water is cooled from 40 ∘c to 0 ∘c. what will happen during cooling?

When water is cooled from to , the temperature of the solution is decreases. Due to decrease in temperature, the intermolecular forces which are present between the solute particles will not break easily.

Decrease in temperature also results in the decrease in solubility. Thus, due to decrease in temperature,   will precipitate implies that the solubility of in water decreases.

Hence, precipitation of occurs.

the answers would be

the first one and the second one

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.