What is the empirical formula if you have 81.82% carbon and 18.18% hydrogen?

May someone me with these science questions

Which substance has non polar covalent bonds

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.