4) 300cm of Hydrogen chloride gas were passed over 7.0g of heated iron fillings until there was no further change. The reaction vessel was then allowed to cool to room temperature. Use the equation below to
determine the mass of iron that remained at the end of the experiment (molar gas volume = 24000cm"; Fe=56).
Fe(s) + 2HCl(g) → FeCl2(s) + H2(g)
(3 mks)
50
3 of IM colution calcium chloride (Avogadro's

The mass of iron that remained at the end of the experiment : 6.65 g

Given

V HCl gas = 300 cm³

mass Fe = 7 g(Ar Fe = 56 g/mol)

Reaction

Fe(s) + 2HCl(g) → FeCl2(s) + H2(g)

Required

The mass of iron remained

Solution

molar volume for 1 mol gas = 24000 cm³=24 L, so mol HCl :

mol ratio Fe : HCl from equation : 1 : 2, so mol Fe =

mass of Iron(reacted) :

Mass remained

7 g - 0.35 = 6.65 g

A) 10 moles of CO and 5 moles O2