can you please answer all of them thank you!

Question 5 Select the compounds that would be named using the Stock System SnF2 Nal HCl CuBr NaOH Question 6 The percentage by mass of water in copper (II) sulfate pentahydrate is Answer to 2 decimal places Select the compounds that are named using prefixes MgO NO CO NaCl CaO H2O Determine the number of moles of P in one mole of calcium phosphate, Ca(PO4)2 1 2 4 8 The molecular formula for acetylene is C2H2. The molecular formula for benzene is C6H6. What is the empirical formula for both? C6H6 (CH)2 CH cannot be determined because they are different compounds