Answer:
5.9 kg
Explanation:
We must work backwards from the second step to work out the mass of oxygen.
1. Second step
Mᵣ: 55.84
Fe₂O₃ + 3CO ⟶ 2Fe + 3CO₂
m/kg: 7.0
(a) Moles of Fe

(b) Moles of CO

However, this is the theoretical yield.
The actual yield is 72. %.
We need more CO and Fe₂O₃ to get the theoretical yield of Fe.
(c) Percent yield

We must use 261 mol of CO to get 7.0 kg of Fe.
2. First step
Mᵣ: 32.00
2C + O₂ ⟶ 2CO
n/mol: 261
(a) Moles of O₂

(b) Mass of O₂

However, this is the theoretical yield.
The actual yield is 71. %.
We need more C and O₂ to get the theoretical yield of CO.
(c) Percent yield

We need 5.9 kg of O₂ to produce 7.0 kg of Fe.
Corrosion of aluminium metal is a chemical process. Corrosion happens when a certain chemical reaction takes place.
Answer:
Explanation:
endergonic
A chemical reaction that has a positive ΔG is correctly described as A) endergonic.
Answer:
the answer is 3.33⋅1023 molecules of Cl2. Note that 6.022⋅1023 is also known as Avogadro's number, and it can be referred to as the number of molecules in one mole of that substance. Also, I calculated 70.9 because 35.45 g/mol (the mass of one Chlorine atom) times 2 is 70.9 g/mol (Cl2 has two Chlorine atoms).
Explanation:
Answer:
A is the closest thing. You change the composition of the steak. You don't in any of the others.
Explanation:
Usually when you cook something, you are doing something to the composition of the object being cooked. A steak might not be obvious, but boiling an egg should be.
Chopping a tree is something physical. You are removing mass in such a way that the tree will fall. There's nothing chemical about that.
Heating a cup of tea looks like it might be chemical. After all steam is sometimes given off which looks like it is chemical. It's not. The water in the tea is just changing phase.
Drying clothes in a dryer. Again, this looks like something might have changed. After all the mass of the clothes just became less. But all you are doing is separating two masses (leaving one of them behind).