Using the balanced chemical reaction below, how many grams of copper (cu) metal can be obtained from 1.00 kg of copper ore (cu3fes3)? 2cu3fes3 (s) + 7o2 (g) ; → 6cu (s) + 2feo (s) + 6so2 (g)

Answer : Mass of copper (Cu) metal obtained = 556.281 g

Solution : Given,

Mass of copper ore = 1 Kg = 1000 g

From the periodic table, the molar mass of copper and copper ore are

Molar mass of copper = 63.546 g/mole

Molar mass of copper ore, = 342.678 g/mole

First we have to calculate the number of moles of copper ore,

Moles of   = = = 2.918 moles

The balanced chemical reaction is :

From this chemical reaction, we conclude that

2 moles of gives          →     6 moles of Cu

2.918 moles of gives   →      

                                                           = 8.754 moles

Thus, the Moles of copper (Cu) = 8.754 moles

Now, calculate the Mass of copper (Cu).

Mass of copper (Cu) = Moles of copper (Cu) × Molar mass of copper (Cu)

                                  = 8.757 moles × 63.546 g/moles

                                  = 556.281 g                                

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.