When 6.7 g of salt are dissolved in 52.1 mL of water, 6888.5 J of heat are given off by the system. How much heat would be given off if only 1.00 g of salt had been dissolved in the water?

the heat absorbed on dissolving 1 g of salt = 1028.13 J

Explanation:

given data

salt dissolve = 6.7 g

water dissolve = 52.1 mL

heat = 6888.5 J

solution

when you dissolve 6.7 g of salt then heat absorbed  = 6888.5 J

and

if dissolve 1 g of salt then heat absorbed = (6888.5 J ÷ 6.7 g) × 1 g

if dissolve 1 g of salt then heat absorbed = 1028.13 J

so that

the heat absorbed on dissolving 1 g of salt = 1028.13 J

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.