What arethe pH, pOH, and concentrations of CO3 2- and HCO3 - after 1.000 mL of 0.1500 M HCl is added to 100.0 mL of 0.0100-M sodium carbonate solution? ignore the added1% volume.
CO3^-2 + H^+ ==> HCO3^-
Calculate mols carbonate to start.
Calculate mols HCl to start.
Subtract carbonate - HCl. You should get 0.85 millimols CO3^-2 left.
You will have formed 0.15 millimols HCO3^-
Divding those by 100 mL will give molarity of carbonate and bicarbonate.
Use pH = pK2 + log(base/acid) to calcualte pH and from there pOH.
Post your work if you run into trouble.
well i just had a question on how to figure out the pk2 value? thank you
pK = -log K
To find the pK2 value, you need to know the equilibrium constant (K) for the reaction between CO3^2- and H+ to form HCO3^-.
The equilibrium constant (K) can be found by using the equation:
K = [HCO3^-] / ([CO3^2-] * [H+])
In this reaction, you know the concentration of CO3^2- and HCO3^- after the reaction, so you can substitute those values into the equation. However, you don't know the concentration of H+ directly.
Since HCl is a strong acid, it will completely dissociate in water, releasing H+. This means that the concentration of H+ can be assumed to be equal to the concentration of HCl that was added.
Using the given information that 1.000 mL of 0.1500 M HCl is added, you can calculate the moles (mols) of HCl that were added. Then, divide the mols of HCl by the final volume of solution (100.0 mL) to get the concentration of H+.
Now that you know the concentrations of [CO3^2-], [HCO3^-], and [H+], you can substitute those values into the equilibrium constant equation. Take the negative logarithm of K to find the pK2 value.
Keep in mind that pK2 refers to the acid dissociation constant for the second ionization of the bicarbonate ion (HCO3^-). You may need to use a reference source or table to find the exact pK2 value for bicarbonate.