Question

When 3243. grams of iron (III) chloride are reacted with 511.8 grams of hydrosulfuric acid, which is the limiting reactant?

2 FeCl3 + 3 H2S -----> Fe2S3 + 6 HCl

Answer 1

Hydrosulfuric acid will act as limiting reactant.

Step-by-step explanation:

Given data:

Mass of iron(III) chloride = 3243.0 g

Mass of hydrosulfuric acid = 511.8 g

Limiting reactant = ?

Solution:

Chemical equation:

2FeCl₃ + 3H₂S → Fe₂S₃ + 6HCl

Number of moles of iron(III) chloride:

Number of moles = mass/molar mass

Number of moles = 3243.0 g/ 162.2 g/mol

Number of moles = 20 mol

Number of moles of hydrosulfuric acid:

Number of moles = mass/molar mass

Number of moles = 511.8 g/ 34.1 g/mol

Number of moles = 15 mol

Now we will compare the moles of both reactant with products

FeCl₃ : Fe₂S₃

2 : 1

20 : 1/2 ×20 = 10

FeCl₃ : HCl

2 : 6

20 : 6/2 ×20 = 60

H₂S : Fe₂S₃

3 : 1

15 : 1/3 ×15 = 5

H₂S : HCl

3 : 6

15 : 6/3 ×15 = 30

Hydrosulfuric acid producing less number of moles of product thus, it will act as limiting reactant.