The percentage yield of the following reaction is 85 %. 2 al, +31--> 2 aici. how many grams of aici, will be actually obtained from 1008 aluminium metal

Assuming the product is AlCl3

Assuming its 1008 g of metalic Al

It will yeld 4234 g of aluminium chloride.

Explanation:

Al molar mass is 26.98 g/mol, so in 1008 g of Al there is 37.36 mols of Al

The stoichometry ratio between Al and AlCl3 is 1:1, so 37.36 mols of Al would form 37.36 mols of AlCl3 if the reaction were complete, but only 85% yelds, so 1008 g of Al makes up to 0.85x37.36 mols of AlCl3 (31.76 moles)

AlCl3 molar mas is 133.33 g/mol, so 31.76 moles has 4234 g

law of conservation of matter

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.