Aluminum sulfate is analyzed, and the sample contains 0.0670 moles of sulfate ions. how many moles of aluminum are in the sample?

0.0447 moles of Aluminum

Explanation:

Break this down to an ionic equation (which may not exist in the real world but it will give you the mol ratios).

Al2(SO4)3 ===> 2Al^(+3) + 3 SO4^(-2)

Now write the equation showing the actual number of moles of SO4^(-2) present. Indicate the Al moles with an x

Al2(SO4)3 ===> 2Al^(+3) + 3 SO4^(-2)

                                x             0.0670  

Now set  up a proportion

2/x = 3/0.0670                             Cross multiply

2*0.0670 = 3x                              Simplify the left

0.134 = 3x                                     Divide both sides by 3

0.134/3 = 3x/3                              Divide

0.0447 = x

there are 0.0447 moles of Aluminum

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.

you need to stop taking that class