Looking for reliable answers? Westonci.ca is the ultimate Q&A platform where experts share their knowledge on various topics. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform.

Problem set1. A) What is the pH of a solution with [H+] = 1 x 10-8 M? 8B) Is this solution acidic or basic? Basic2. A) What is the [OH-] of a solution that has an [H+] = 1 x 10-4 M? 10B) Is this solution acidic or basic? Basic3. What is the [OH-] of a solution that has a pH of 2?4. A) The pH of a solution is changed from pH 6 to pH 10. Does this reflect an increase or decrease in [H+]?B) By how much has the [H+] changed?5. A) If a solution at pH 5 undergoes a 1000-fold increase in [H+], what is the resulting pH?B) If a solution at pH 5 undergoes a 1000-fold increase in [OH-], what is the resulting pH?

Sagot :

2. The pH scale is well used in Chemistry to determine if a solution will be considered to be acidic or basic, and this definition is due to the concentration of protons, which you can also see as H+, and Hydroxide ions, which is also OH-, for concentration, it is usually represented with this symbol []. Now to find out what is the pH of a substance, we can use the pH formula, which is:

pH = -log [H+]

For example we have in question number 1

pH = -log [1*10^-8]

pH = 8

Therefore it will be a basic compound, because the pH scale is divided into below 7 and over 7, <7 = acidic, which also means a high concentration of H+.

>7 = basic, which also means a low concentration of H+

But if we make this simple calculation 7+7 we will have 14, which is the higher number from the pH scale, and this thought when it comes to concentration of ions will be describe as:

1*10^-14 = (1*10^-7) * (1*10^-7)

This is also represented by this equation:

Kw = [H+] * [OH-], where Kw is the constant for pure water

So from this math you realize that if we increase H+, we need to decrease OH-, the same goes for OH-, this is why substances are basic or acids

Now into our question

2. A) if the solution has a concentration of H+ = 1*10^-4, this means that the pH is 4, and 14 (higher value) - 4 = 10, therefore the concentration of OH- must be really low, which is 1*10^-10, or simply 10

B) If the solution has a [H+] = 1*10^-4, the pH will be 4, therefore the solution will be acidic