Please help and explain please

What is the percentage by mass of silicon (si) in iron aluminum silicate (fe3al2(sio4)3)?

Label a-f based on the table using c for concentrated and d for dilute

4.25g sample of solid ammonium nitrate dissolves in 60.0g of water in a coffee-cup calorimeter, the temperature drops from 22.0 c to 16.9 c. assume that the specific heat of the solution is the same as that of pure water. calculate delta(h) (in kj/mol nh4no3) for the solution proces.