The pH of lemon juice at 298 K is found to be 2.32. What is the concentration of [tex]$H _3 O ^{+}$[/tex] ions in the solution?

Use [tex]$\left[ H _3 O ^{+} \right] = 10^{-\text{pH}}$[/tex].

A. [tex][tex]$1.05 \times 10^{-3} \, M$[/tex][/tex]
B. [tex]$4.79 \times 10^{-3} \, M$[/tex]
C. [tex]$2.09 \times 10^2 \, M$[/tex]
D. [tex][tex]$9.55 \times 10^2 \, M$[/tex][/tex]



Answer :

To find the concentration of [tex]\( \left[ H_3O^+ \right] \)[/tex] ions in lemon juice given that its pH is 2.32, you can use the relationship between pH and hydronium ion concentration:

[tex]\[ \left[ H_3O^+ \right] = 10^{-pH} \][/tex]

Here’s a step-by-step solution to compute the concentration:

1. Understand the given value:
The pH of the lemon juice is 2.32.

2. Write down the formula for hydronium ion concentration:
[tex]\( \left[ H_3O^+ \right] = 10^{-pH} \)[/tex]

3. Substitute the pH value into the formula:
[tex]\( \left[ H_3O^+ \right] = 10^{-2.32} \)[/tex]

4. Calculate the power of 10:
When calculating [tex]\( 10^{-2.32} \)[/tex], you get approximately [tex]\( 0.004786300923226385 \)[/tex].

5. Express the result in scientific notation:
* The result [tex]\( 0.004786300923226385 \)[/tex] can be rewritten as [tex]\( 4.79 \times 10^{-3} \)[/tex].

Therefore, the concentration of [tex]\( \left[ H_3O^+ \right] \)[/tex] ions in the lemon juice is:

[tex]\[ 4.79 \times 10^{-3} \, \text{M} \][/tex]

Among the given options:

- [tex]\( 1.05 \times 10^{-3} \, \text{M} \)[/tex]
- [tex]\( 4.79 \times 10^{-3} \, \text{M} \)[/tex]
- [tex]\( 2.09 \times 10^2 \, \text{M} \)[/tex]
- [tex]\( 9.55 \times 10^2 \, \text{M} \)[/tex]

The correct answer is [tex]\( 4.79 \times 10^{-3} \, \text{M} \)[/tex].