Question

Aluminum metal and manganese (IV) oxide react to produce aluminum oxide and manganese metal. What mass of manganese (IV) oxide reacts to produce 1.12kg of manganese metal?

Answer 1

Answer: 1.77 kg of manganese (IV) oxide reacts to produce 1.12kg of manganese metal.

Step-by-step explanation:

The balanced chemical equation is:

`4Al+3MnO_2\rightarrow 2Al_2O_3+3Mn`

To calculate the moles, we use the equation:

`\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}`

moles of manganese =
`(1.12* 1000g)/(55g/mol)=20.4mol`

According to stoichiometry :

3 moles of
`Mn` is produced by = 3 moles of
`MnO_2`

Thus 20.4 moles of
`Mn` is produced by =
`(3)/(3)* 20.4=20.4moles` of
`MnO_2`

Mass of
`MnO_2=moles* {\text {Molar mass}}=20.4moles* 86.9g/mol=1773g=1.773kg` (1kg=1000g)

Thus 1.77 kg of manganese (IV) oxide reacts to produce 1.12kg of manganese metal.