Question

2. The alkalinity of a fluid (pH) can be modeled in terms of its hydrogen ion concentration (H+, measured in moles/liter) of the fluid using the model shown below:pH = - log(H^+)A lab technician finds that a sample of fluid has a pH of 4.5. What is the hydrogen ion concentration of the fluid?

Answer 1

Given the equation:

$pH=-log\mleft(H^+\mright)$

You know that a lab technician finds that a sample of fluid has this pH:

$pH=4.5$

Then, in order to find the hydrogen ion concentration of the fluid, you need to follow these steps:

1. Substitute the pH given in the exercise into the equation:

$4.5=-log(H^+)$

Multiply both sides by -1:

$-4.5=\log (H^+)$

2. Solve for:

$H^+$

Remember that, by definition:

$\log _b\mleft(c\mright)=a\Rightarrow b^a=c$

In this case, you can identify that:

$\begin{gathered} a=-4.5 \\ b=10 \\ c=H^+ \end{gathered}$

Hence, substituting values and simplifying, you get:

$\begin{gathered} b^a=c \\ 10^{-4.5}=H^+ \\ H^+=0.00003162278\text{ }\frac{moles}{liter} \end{gathered}$

Therefore, the answer is:

$H^+=0.00003162278\text{ }\frac{moles}{liter}$