A weak acid dissociates according to the reaction HAH^+ + A^-. What would adding more acid do to the pH? Explain your answer based on the Ka of the acid.

Question

A weak acid dissociates according to the reaction HA<-->H^+ + A^-. What would adding more acid do to the pH? Explain your answer based on the Ka of the acid.

rushwr · Answer

Any idea about that ? ^_^ @asiannerd

asiannerd · Answer

Nope

rushwr · Answer

So this is a weak acid which means it dissociates partially unlike HCL which dissociate fully

rushwr · Answer

pH = -log{H^+}
Which means when the hydrogen concentration increase the pH decreases

rushwr · Answer

What I meant by hydrogen concentration is the dissociated amount. normally pH ranging from 1 to 6 is called acidic 
7 is neutral and 8 to 14 is basic 
okai ? 
Since HA is a weak acid it will have a an high acidic pH (when hydrogen ion concentration is low the pH increase)  which is around 5 or 6 
Adding some more of the WEAK acid won't do a huge difference in pH because it can't give out a lot of H^+ ions so the hydrogen concentration is low. Anyhow the free H^+ ion concentration increases slightly thus the pH will decrease slightly in  the acidic range,,,,, So we can say pH will slightly decrease !