A sample of N2 has a volume of 616 mL at 68 °C. What will be its volume at -17 °C?

462.5ml

Explanation:

Using Charle's law equation;

V1/T1 = V2/T2

Where;

V1 = initial volume (ml)

V2 = final volume (ml)

T1 = initial temperature (K)

T2 = final temperature (K)

Based on the information provided in this question;

V1 = 616ml = 616/1000 = 0.616L

V2 = ?

T1 = 68°C = 68 + 273 = 341K

T2 = 17 °C = -17 + 273 = 256K

V1/T1 = V2/T2

0.616/341 = V2/256

Cross multiply

341 × V2 = 256 × 0.616

341V2 = 157.69

V2 = 157.69/341

V2 = 0.4625 L or 462.5ml

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.