Question

How many grams of O2 are required to precipitate all the iron in 75 mL of 0.090 M Fe2+?

Answer 1

mass O₂ required : 0.054 g

Further explanation

The reaction equation is the chemical formula of reagents and product substances

A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products

Reaction

4Fe(OH)⁺ (aq) + 4OH⁻ (aq) + O₂ (g)+ 2H₂O (l)⇒ 4Fe(OH)₃ (s)

To precipitate Fe²⁺(in Fe(OH⁺) to Fe³⁺(in Fe(OH)₃)

• mol Fe²⁺

`\tt 75* 0.09=6.75~mlmol=6.75* 10^(-3)mol`

mol ratio from equation = mol O₂ :mol Fe(OH) = 1 : 4

• mol O₂

`\tt (1)/(4)* 6.75* 10^(-3)=1.6875* 10^(-3)`

• mass O₂

`\tt mass=mol* MW\\\\mass=1.6875* 10^(-3)* 32=5.4* 10^(-2)~g`