A reaction involved in the production of iron from iron ore is: Fe2O3(s)
CO (g)
Fe (s)
CO2
a) How many kilograms of CO must react to produce 3.50 kg of Fe?
b) What mass of CO, would be produced?

a) 2.632 kg

b) 41.36 kg

Explanation:

Given data:

Mass of CO react = ?

Mass of Fe formed = 3.50 Kg (3.50 /1000 =3500 g)

Mass of CO₂ formed = ?

Solution:

Chemical equation;

Fe₂O₃ + 3CO     →   2Fe + 3CO₂

Number of moles of Fe:

Number of moles = mass/molar mass

Number of moles =  3500 g/55.85 g/mol

Number of moles = 62.67 mol

now we will compare the moles of iron with CO.

            Fe         :       CO

             2          :       3

          62.67     :        3/2×62.67 = 94 mol

Mass of CO:

Mass = number of moles × molar mass

Mass = 94 mol × 28 g/mol

Mass = 2632 g

In kilogram:

2632g × 1 Kg /1000 g

2.632 kg

Now we will compare the moles of Fe with CO₂

                 Fe         :           CO₂

                  2          :           3

               62.67     :        3/2×62.67 = 94 mol

Mass of CO₂:

Mass = number of moles × molar mass

Mass = 94 mol × 44 g/mol

Mass = 4136 g

In kilogram:

4136g × 1 Kg /1000 g

41.36 kg

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.