PLEASE HELP ME!! The black balls represent carbon atoms and the white balls represent Hydrogen atoms

A: C3H8
B: C3H10
C: 3CH
D: 3CH8

How many liters of oxygen gas, at standard temperature and pressure, will react with 35.8 grams of iron metal? 4 fe (s) + 3 o₂ (g) → 2 fe₂o₃ (s)

If a solution contains 3 moles/liter of sodium chloride (nacl, made of sodium ions and chloride ions), what is the osmolarity of this solution

Consider the reaction: 2al(s) + fe2o3(s) → al2o3(s) + 2fe(s) the δhf for fe2o3(s) = -824.3 kj/mole. the δhf for al2o3(s) = -1675.7 kj/mole. finish the equation. δhrxn = [(1)( kj/mole) + (2)( kj/mole)] - [(1)( kj/mole) + (2) ( kj/mole)]