Question

Which oxide(s) of manganese have a mass percent of the metal that is greater than 50%?MnO MnO2 Mn2O3All of these102

Answer 1

Answer:

All of these

Explanation:

In MnO:

mass of Mn = 55 g (as 1 mole of Mn weighs 55 g)

mass of O = 16 g    (as 1 mole of O weighs 16 g)

The mass percent of metal Mn= $\frac{55}{55+16}\times100=\frac{55}{71}\times100=77.46$

In MnO2:

mass of Mn = 55 g

mass of O = 2*16 = 32 g

The mass percent of metal Mn=$\frac{55}{87}\times100=63.22$

In Mn2O3:

mass of Mn = 2*55 = 110 g

mass of O = 3*16 = 48 g

The mass percent of metal Mn=$\frac{110}{158}\times100=69.62$

In all the cases the mass percent of metal is greater than 50.