Consider the unbalanced equation for the full neutralization of citric acid:

[tex]\[
H_3C_6H_5O_7(aq) + Ba(OH)_2(aq) \rightarrow H_2O(l) + Ba_3\left(C_6H_5O_7\right)_2(aq)
\][/tex]

Balance the equation and determine how many moles of [tex]\[ Ba(OH)_2 \][/tex] are required to completely neutralize 8.762 mol of [tex]\[ H_3C_6H_5O_7 \][/tex].

A. 0.508 mol [tex]\[ Ba(OH)_2 \][/tex]

B. 0.254 mol [tex]\[ Ba(OH)_2 \][/tex]

C. 0.762 mol [tex]\[ Ba(OH)_2 \][/tex]

D. 2.29 mol [tex]\[ Ba(OH)_2 \][/tex]

E. 1.14 mol [tex]\[ Ba(OH)_2 \][/tex]



Answer :

To determine how many moles of [tex]\( \text{Ba(OH)}_2 \)[/tex] are required to completely neutralize 8.762 moles of [tex]\( \text{H}_3\text{C}_6\text{H}_5\text{O}_7 \)[/tex], we need to balance the chemical equation first and then use the stoichiometric relationship.

1. Balance the chemical equation:

The given unbalanced equation is:
[tex]\[ \text{H}_3\text{C}_6\text{H}_5\text{O}_7(aq) + \text{Ba(OH)}_2(aq) \rightarrow \text{H}_2\text{O}(l) + \text{Ba}_3(\text{C}_6\text{H}_5\text{O}_7)_2(aq) \][/tex]

To balance the equation, we need to match the number of atoms of each element on the reactants side with those on the products side.

- Balance the Ba atoms:
[tex]\[ \text{Ba(OH)}_2(aq) \rightarrow \text{Ba}_3(\text{C}_6\text{H}_5\text{O}_7)_2(aq) \][/tex]
Since there are 3 Ba atoms on the product side, we need 3 Ba atoms on the reactants side:
[tex]\[ \text{3 Ba(OH)}_2(aq) \][/tex]

- Balance the Citric Acid ([tex]\( \text{H}_3\text{C}_6\text{H}_5\text{O}_7 \)[/tex]):
[tex]\[ 2 \text{H}_3\text{C}_6\text{H}_5\text{O}_7(aq) \][/tex]

- Now, let's balance the Hydrogen (H) and Oxygen (O) atoms:
The total H atoms in the reactants:
[tex]\[ 2 \times 3 (\text{H}) + 3 \times 2 (\text{OH}) = 6 \text{H} + 6 \text{OH} \][/tex]
This breaks into 6 molecules of water ([tex]\(\text{H}_2\text{O}\)[/tex]):
[tex]\[ 6 \text{H}_2\text{O}(l) \][/tex]

The balanced equation is therefore:
[tex]\[ 2 \text{H}_3\text{C}_6\text{H}_5\text{O}_7(aq) + 3 \text{Ba(OH)}_2(aq) \rightarrow 6 \text{H}_2\text{O}(l) + \text{Ba}_3(\text{C}_6\text{H}_5\text{O}_7)_2(aq) \][/tex]

2. Determine the moles of [tex]\(\text{Ba(OH)}_2\)[/tex] required:

From the balanced equation, we see that 2 moles of [tex]\(\text{H}_3\text{C}_6\text{H}_5\text{O}_7\)[/tex] require 3 moles of [tex]\(\text{Ba(OH)}_2\)[/tex]:

The mole ratio of [tex]\(\text{H}_3\text{C}_6\text{H}_5\text{O}_7\)[/tex] to [tex]\(\text{Ba(OH)}_2\)[/tex] is:
[tex]\[ \frac{3}{2} \][/tex]

Given [tex]\( 8.762 \)[/tex] moles of [tex]\(\text{H}_3\text{C}_6\text{H}_5\text{O}_7\)[/tex]:
[tex]\[ \text{Moles of } \text{Ba(OH)}_2 = 8.762 \times \frac{3}{2} = 13.143 \text{ moles} \][/tex]

Hence, 13.143 moles of [tex]\(\text{Ba(OH)}_2\)[/tex] are required to completely neutralize 8.762 moles of [tex]\(\text{H}_3\text{C}_6\text{H}_5\text{O}_7\)[/tex].