Question

PH of 0.015 M HCL is?

Answer 1

I get `1.82`.

Explanation:

`"pH"` is given by the equation,

`"pH"=-log[H^+]`

• `[H^+]` is the hydrogen ion concentration in terms of molarity.

Since hydrochloric acid is a strong acid, it dissociates into single `H^+` ions in an aqueous solution, which eventually become `H_3O^+` ions due to the presence of water `(H_2O)`, and the `"pH"` will simply be:

`"pH"=-log(0.015)`

`~~1.82`

Answer 2

See below.

Explanation:

`HCl` is a strong acid. That means that it dissociates completely into `H^+` and `Cl^-`:

`"HCl"_((aq)) -> "H"^+ + "Cl"^-`

This means that the initial concentration of `HCl` is equal to the equilibrium concentration of `H^+`.

Therefore, `["HCl"]=["H"^+]`, and `["H"^+]=0.015" M"` at equilibrium.

Here is an equation that you will need to be familiar with in order to solve this problem:

`pH=-log["H"^+]`

Now, we take our concentration of `["H"^+]=0.015" M"` and plug it in as the equilibrium concentration of `["H"^+]` at equilibrium in the equation, and solve for the `pH`. Here is the setup to obtain the final answer:

`pH=-log[0.015]`

Plug this into your calculator, and the answer will be `color(red)(1.82`, with significant figures (note that the digit `1` in the answer does not count as a significant figure. If you need help with significant figures and pH, please leave a comment.)

I hope that helps!