The reaction between aluminium and ferric oxide can generate temperatures up to 3273 K and is used in welding metals. (Atomic mass of Al = 27 u Atomic mass of 0 = 16 u) `2Al + Fe_(2)O_(3) to Al_(2)O_(3)+ 2Fe`, If, in this process, 324 g of aluminium is allowed to react with 1.12 kg of ferric oxide.
(i) Calculate the mass of `Al_(2)O_(3)` formed.
(ii) How much of the excess reagent is left at the end of the reaction?

Explanation

Given : `2Al+Fe_(2)O_(3)rarrAl_(2)O_(3)+2F_(e)`

Molar mass of `Al_(2)O_(3)` formed `=6molxx102gmol^(-1)`
`{:[(Al_(2)O_(3)),((2xx27)+(3xx16)),(54+48=102):}]=612g`
Excess reagent `=Fe_(2)O_(3)`
Amount of excess reagent left at the end of the reaction
`=1molxx160mol^(-1)`
`=160g{:[(Fe_(2)O_(3)),((2xx56)+(3xx16)),(112+48=160):}]=160g`