What mass of iron oxide 3 is formed during the decomposition of 21.4 g of iron hydroxide 3?

1. Let’s compose the reaction equation for the decomposition of iron hydroxide (3):

2Fe (OH) 3 = Fe2O3 + 3H2O;

2.Calculate the chemical amount of hydroxide:

n (Fe (OH) 3) = m (Fe (OH) 3): M (Fe (OH) 3);

M (Fe (OH) 3) = 56 + 3 * 16 + 3 = 107 g / mol;

n (Fe (OH) 3) = 21.4: 107 = 0.2 mol;

3. Determine the amount of formed iron oxide (3):

n (Fe2O3) = n (Fe (OH) 3): 2 = 0.2: 2 = 0.1 mol;

4.Calculate the mass of the oxide:

m (Fe2O3) = n (Fe2O3) * M (Fe2O3);

M (Fe2O3) = 2 * 56 + 3 * 16 = 160 g / mol;

m (Fe2O3) = 0.1 * 160 = 16 g.

Answer: 16 g.