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.
You can tell if its a living thing from a microscope by its movement
NaCl - also known as sodium chloride or table salt; an ionic bond; it’s a chemical compound, so both
SO2 - also known as sulfur dioxide; a covalent bond; nonmetal
CaO - also known as calcium oxide; an ionic bond; metal
HF - also known as hydrogen fluoride; polar covalent; metal
NO2 - also known as nitrogen dioxide; covalent; nonmetal
H2O - also known as water; covalent; nonmetal
Answer:
Eºcell = -1.78 V
Explanation:
The Eº cell is an intensive property, i.e they do not depend on the quantity of material present and the desired reaction in our problem is exactly half the reverse of the one given, the Eºcell will then be the negative of the first then Eºcell is -1.78 V and the redox reaction will be non-spontaneous as opposed to the first.