The molar mass of oxygen gas (o2) is 32.00 g/mol. the molar mass of c3h8 is 44.1 g/mol. what mass of o2, in grams, is required to completely react with 0.025 g c3h8?

You are given O2 and C3H8, this is a combustion reaction. The chemical reaction is C3H8 + 10O2 à 3CO2 + 4H2O. You are also given the molar mass of O2 which is 32.00 g/mol and C3H8 which is 44.1 g/mol. You are required to find the mass of O2 in grams. Since you have the reaction, oe mole of C3H8 is required to completely react 10 moles of O2. So,  

0.025g C3H8(1 mol C3H8/44.1 g C3H8)(10 mol O2/1 mol C3H8)(32 g O2/1 mol O2) = 0.1802 g O2  

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic