If a solution contains 0.0100 mole of HCl in 10.0 mL aqueous solution.
a.) What is its molarity? My answer is 1M (0.0100 mole/10.0 mL * 1000 mL/1L = 1M)
b.) What is H^+ ion concentration for this solution?
c.) What is the expected pH for this solution?
pls help i don't know how to answer the last 2 questions
You're batting 1000 on a. Just plug in the numbers for b and c.
b.
HCl is a strong acid (meaning it ionizes 100%) so HCl ==> H^+ + Cl^-
If HCl = 1.0 M then (H^+) must be 1.0 M (and Cl^- must be 1.0 M).
c.
pH = -log(H^+)
pH = -log(1.0)
pH = -(0)
pH = 0
(Note: I doubt it would read this on a pH meter).
Well, let's dive into it and have some fun with chemistry!
a.) You're right! The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution in liters. So, in this case, 0.0100 moles of HCl divided by 0.0100 L gives you a molarity of 1.00 M. Good job!
b.) Now, to find the H+ ion concentration, we need to remember that one mole of HCl will produce one mole of H+ ions. So, with 0.0100 moles of HCl in 0.0100 L, we have 0.0100 M of H+ ions. There you go!
c.) Ah, pH, the infamous scale of acidity. To find the pH, we'll use the relationship between pH and H+ concentration. The pH scale ranges from 0 to 14, with 7 being neutral. Since our H+ concentration is 0.0100 M, we take the negative logarithm of that to get the pH. Plugging it in:
pH = -log(0.0100) ≈ 2.00
So, the expected pH for this solution is around 2.00.
Hope that helps! If you have any more chemistry conundrums, just ask!
To answer the last two questions, we need to consider the dissociation of HCl in water. HCl is a strong acid that completely dissociates into H+ and Cl- ions in water.
a.) The molarity of the solution is indeed 1M, as you correctly calculated.
b.) In this case, since HCl is a strong acid, it dissociates completely to form H+ ions. Therefore, the H+ ion concentration is also 1M.
c.) The pH of a solution is a measure of its acidity. It is defined as the negative logarithm (base 10) of the H+ ion concentration. So, in this case, the pH can be calculated as -log10(1). Since the log of 1 is 0, the pH of this solution is 0.
Therefore, the answers are:
b.) H+ ion concentration: 1M
c.) pH: 0
To answer parts b) and c), we need to understand the properties of the HCl molecule. HCl is a strong acid that dissociates completely in water, meaning it fully breaks down into its ions: H+ and Cl-.
b) The H+ ion concentration for this solution is equal to the molarity of HCl. So, in this case, the H+ ion concentration is also 1M.
c) The pH of a solution can be calculated using the formula: pH = -log[H+]. In this case, since the H+ ion concentration is 1M, we can calculate the pH as follows:
pH = -log(1) = 0
Therefore, the expected pH for this solution is 0.
Please note that pH is a negative logarithmic scale, which means that lower pH values indicate more acidic solutions. In this case, the solution is extremely acidic.