I believe it would be the first option. It forms iron oxide (rust) when exposed to moisture and air.
        
                    
             
        
        
        
It is greater than the total mass
        
             
        
        
        
Answer:
HCO₂
Explanation:
From the information given:
The mass of the elements are:
Carbon C = 26.7 g;     Hydrogen H = 2.24 g     Oxygen O = 71.1 g
To determine the empirical formula;
First thing is to find the numbers of moles of each atom.
For Carbon:

For Hydrogen:

For Oxygen:

Now; we use the smallest no of moles to divide the respective moles from above.
For carbon:

For Hydrogen:

For Oxygen:

Thus, the empirical formula is HCO₂
 
        
             
        
        
        
Answer:
The ratio of staggered to eclipsed conformers is 134
Explanation:
It is possible to determine the ratio of staggered to eclipsed conformers of a reactant, using the equilibrium:
Staggered ⇄ Eclipsed
Keq = [Eclipsed] / [Staggered]
That means Keq is equal to the ratio we need to find:
Using:
G˚= -RTln Keq
<em>Where G° = -12133.6J/mol</em>
<em>R is gas constant: 8.314J/molK</em>
<em>T is absolute temperature: 298K</em>
<em />
-12133.6J/mol= -8.314J/molK*298K ln Keq
4.8974 = ln Keq
134 = Keq = [Eclipsed] / [Staggered]
<h3>The ratio of staggered to eclipsed conformers is 134</h3>