Answer:
28.9%
Explanation:
Let's consider the following balanced equation.
2 FeS₂ + 11/2 O₂ ⇒ Fe₂O₃ + 4 SO₂
We can establish the following relations:
- The molar mass of Fe₂O₃ is 159.6 g/mol
- 1 mole of Fe₂O₃ is produced per 2 moles of FeS₂
- 1 mole of Fe is in 1 mole of FeS₂
- The molar mass of Fe is 55.84 g/mol
The amount of Fe in the sample that produced 0.516 g of Fe₂O₃ is:

The percent of Fe in 1.25 g of the ore is:

In 1871, a Russian Chemist, Dimitri Mendeleev, gave a useful scheme for classification of elements. He presented the first regular periodic table in which elements of similar chemical properties were arranged in eight vertical columns called groups. The horizontal rows of table were called periods. He arranged elements in ascending order of their atomic masses and found that elements having similar chemical properties appeared at regular intervals. This observation was called Periodic Law.
Answer: This is called moles
Explanation: This is described to be the number of molecules, atoms or ions in a substance :)
Answer:
11419 J/g/ 11.419 KJ/g
Explanation:
H=MCQ
H=225×2.03×(-15-10)
H=225×2.03(25) Note; negative sign is of no use
H=11419J/g