1) in periodic acid (HIO₄), iodine has oxidation number +7, hydrogen has oxidation number +1, oxygen has -2, compound has neutral charge:
+1 + x + 4 · (-2) = 0.
x = +7.
2) in molecule of iodine (I₂), iodine has oxidation number 0, because iodine is nonpolar molecule.
3) in sodium iodide (NaI), iodine has oxidation number -1, sodium has oxidation number +1:
+1 + x = 0.
x = -1.
4) in iodic acid (HIO₃), iodine has oxidation number +5, hydrogen has oxidation number +1, oxygen has -2, compound has neutral charge:
+1 + x + 3 · (-2) = 0.
x = +5.
Answer:
0.71
Explanation:
The molecular mass of NaCl is, 23+35.5
= 58.5
1 mole means molecular mass (in gram)
In 58.5 gm NaCl there is 1 mole.
So, 42.1 gm NaCl contains 42.1/58.5 =0.71 moles.
The electons are in the atmosphere
21.69mL - 20.70mL = .99mL Fe
7.8 g / .99 mL = 7.9g/mL
