In an experiment, 25 ml of 0.5 M CH3COOH was titrated against 0.5 M NaOH solution using phenolphthalein as indicator. The end point is reached when 25 mL of NaOH solution was added. i) Determine the concentration of the product.

ii) Determine the pH of the solution at the end point.

1 is the answer to this problem

i think its 100

i hope this !

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.