Question

Question #dc69a

Answer 1

`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`