What is digital vs analog? what is an example of each?

How many grams of iron can be made from 16.5 grams of fe2o3

15) a substance used in manufacturing gasoline consists of finely divided platinum supported on an inert solid. suppose that the platinum is formed by the high temperature reaction between platinum (iv) oxide and hydrogen gas. the other product is water. a) write and balance the equation b) how many grams of hydrogen are needed to produce 1.0 g of platinum metal? c) how many moles of water are produced at the same time? how many grams? ( show work, .)

What kind of chemical reaction does the chemical equation sodium + chlorine → sodium chloride represent? a. combustion b. decomposition c. single replacement d. synthesis