Use graham's law to calculate how much faster fluorine gas, f2 , will effuse than chlorine gas, br2, will the molar mass of f2=38.0; the molar mass of br2=160

    Fluorine gas   effuses 1.37  times faster than  chlorine  gas

   calculation
Rate  of  F2/rate  of Cl2  =√  molar mass    Cl2 /  molar mass F2
rate  of  F2/Rate of Cl2  = √1.868

rate  of  F2/rate of Cl2 =√  71/38    = 1.37   times faster than chlorine

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