Answer:
4.2 g
Explanation:
The VOLUME of the ring is 4.2 - 4.0 = .2 ml = .2 cm^3
the MASS of the ring is this times the density
.2 cm^3 * 21 g/cm^3 = 4.2 g
Answer is: <span>the charge of the iron in this compound is +2.
Atomic mass of iron is 55,8 g/mol.
Atomic mass of chlorine is 35,5 g/mol.
If compound is FeCl, molar mass would be 55,8 </span>g/mol + 35,5 g/mol = 91,3 g/mo, that is not correct.
If compound is FeCl₂, malar mass of compound would be:
55,8 g/mol + 2·35,5 g/mol = 126,8 g/mol, that is correct.
Oxaidation number of chlorine is -1.
2KClO₃ → 2KCl + 3O₂
mole ratio of KClO₃ to O₂ is 2 : 3
∴ if moles of O₂ = 5 mol
then moles of KClO₃ =

= 3.33 mol
Mass of KClO₃ needed = mol of KClO₃ × molar mass of KClO₃
= 3.33 mol × ((39 × 1) + (35.5 × 1) + (16 × 3) g/mol
= 407.93 g
Hello Naphya,
Question - What Energy Form Is A Bow And Arrow
Answer - Potential Energy
Why - "The energy is stored in the limbs in the form of potential energy; when the string is released the energy stored into the limbs is released, most of which is absorbed by the arrow."