Acompound composed of nickel and fluorine contains 9.11 g ni and 5.89 g f. what is the empirical formula of this compound

Empirical formula is the simplest formula showing the simplest ratio of atoms in a compound. Calculated as shown;
 we start by calculating the number of moles of each atom;
moles of nickel = 9.11 g ÷ 58.7 g = 0.155 moles 
moles of fluorine = 5.89 g ÷ 19 g = 0.31 moles
Then we get the ratio of the moles of nickel to that of flourine
 That is 0.155 : 0.31  (dividing by the smallest)
            0.155/0.155 : 0.31/0.155
we get 1:2  ( the simplest ratio)
Therefore the empirical formula is nif2 

Hno3(aq) → h+(aq) + no3−(aq). picture ii best represents the strong acid hno3. strong acids are strong electrolytes