Question

Timed PLS help

Given the following reaction:

2 Al + 2 KOH + 4 H2SO4 + 22 H2O --> 3 H2 + 2KAl(SO4)2•12H2O

If you start with 8.3 mL of 9.9M sulfuric acid, what is the theoretical yield of alum?

Answer 1

19.5g is the theoretical yield of alum

Step-by-step explanation:

Based on the balanced reaction, 4 moles of sulfuric acid produce 2 moles of alum. To solve this question we need to find the moles of H2SO4. With these moles we can find the moles of alum and its mass assuming all sulfuric acid reacts producing alum.

Moles Sulfuric Acid:

8.3mL = 0.0083L * (9.9mol/L) = 0.08217 moles sulfuric acid

Moles Alum:

0.08217 moles sulfuric acid * (2mol KAl(SO4)2•12H2O / 4mol H2SO4) =

0.041085 moles KAl(SO4)2•12H2O

Mass Alum -Molar mass: 474.3884 g/mol-

0.041085 moles KAl(SO4)2•12H2O * (474.3884 g/mol) =

19.5g is the theoretical yield of alum