C) if 0.66 mole of iron (iii) oxide were produced from the reaction, that must mean that how many mole
of oxygen reacted?

If there is 0.66 moles of iron(III)oxide produced, there reacte 0.99 moles of oxygen (O2)

Explanation:

Step 1: Data given

Number of moles iron (III) oxide (Fe2O3) = 0.66 moles

Step 2: The balanced equation

4Fe + 3O2 → 2Fe2O3

Step 3: Calculate moles of oxygen (O2)

For 4 moles Fe consumed, we need 3 moles of O2 to produce 2 moles of Fe2O3

For 0.66 moles Fe2O3 produced, we need 3/2 * 0.66 = 0.99 moles of O2

If there is 0.66 moles of iron(III)oxide produced, there reacte 0.99 moles of oxygen (O2)

c (diamond),

sio2 (quartz)

i think   the answer is c hope i'm right