Question #dc69a

1 Answer
Apr 22, 2016

Answer:

#9.45g#

Explanation:

ok so first find the moles of iron in #19.69g#
use the formula #mol=(mass)/(ar)# ar is the atomic relative mass.
#mol=19.69/56#
#mol=0.3516approx0.35#
now from the equation we know that 2 moles of aluminium make 2 moles of iron.now use the ratio method to get the moles of aluminium in #0.35mols#.so it will be #0.35mols# as they both have the same ratio.
so now use these moles to find the mass of aluminium
#mol=(mass)/(ar)#
#0.35*27=mass#
#9.45g#