Which of the following statements `is//are` correct"
The following reaction occurs:
`2Al + 3MnO overset(Delta)rarr Al_(2) O_(3) + 3 Mn`.
`108.0 g` of `Al` and `213.0 g` of `MnO` was heated to initiate the reaction. `(Mw "of" MnO = 71`, atomic weight of `Al = 13)`

Options

A. `Al` is present in excess
B. `MnO` is present is excess.
C. `54.0 g` of `Al` is required
D. `159.0 g` of `MnO` is in excess.

Answer

A, C

Explanation

Moles of `Al = (108)/(27) = 4.0 "mol"`
moles of `MnO = (213)/(71) = 3.0 "mol"`
a. Since 2 mol of `Al` requires 3 mol of `MnO`, therefore `Al` is in excess.
b. Wrong
Weight of `Al` required
`= (3.0 "mol" MnO) ((2 "mol" Al)/(2 "mol" MnO))((27 g Al)/("mol" Al))`
`= (3 xx 2 xx 27)/(3) = 54.0 g` of `Al`
d. Weight of `Al` in excess `= (108 - 54) = 54.0 g`