How many (a) H+ ions (1 g-ion/L = 6.023 x 1023 ions/L) and (b) OH- ions are present in 250 ml of a solution of pH 3?
To determine the number of H+ ions and OH- ions in a solution of pH 3, we need to know the concentration of H+ ions (in moles per liter).
The pH of a solution is defined as the negative logarithm (base 10) of the concentration of H+ ions. Mathematically, we can express it as:
pH = -log[H+]
To convert the pH to [H+], we can rearrange the equation and solve for [H+]:
[H+] = 10^(-pH)
For this particular problem, we have a pH of 3. Substituting this value into the equation, we get:
[H+] = 10^(-3)
Now that we have the concentration of H+ ions in moles per liter, we can calculate the number of H+ ions in 250 ml of solution.
Step 1: Convert 250 ml to liters.
250 ml = 0.250 liters
Step 2: Multiply the concentration of H+ ions by the volume in liters.
Number of H+ ions = [H+] x Volume
Number of H+ ions = 10^(-3) x 0.250
To calculate the number of H+ ions, we need the Avogadro's number (6.023 x 10^23 ions/L) given in the question.
(a) Number of H+ ions = (10^(-3) x 0.250) x (6.023 x 10^23 ions/L)
Similarly, we know that water is neutral, which means that the concentration of H+ ions is equal to the concentration of OH- ions in pure water. So, the number of OH- ions will be the same as the number of H+ ions in this case.
(b) Number of OH- ions = (10^(-3) x 0.250) x (6.023 x 10^23 ions/L)
Now we can calculate the number of H+ ions and OH- ions using these formulas.