<u>Answer:</u> The mass of
present in the sample is 1.440 g
<u>Explanation:</u>
The chemical equation follows:

From the above equations, it is visible that number of moles of
is formed by half the number of moles of 
To calculate the number of moles, we use the equation:
.....(1)
Given mass of iron (III) oxide = 0.413 g
Molar mass of iron (III) oxide = 159.70 g/mol
Putting values in equation 1, we get:

Calculating number of moles of 
Number of moles of 
Calculating the mass of
using equation 1, we get:
Moles of 
Molar mass of
= 278.01 g/mol
Putting values in equation 1, we get:

Hence, the mass of
present in the sample is 1.440 g