Unit 2 Flashcards
In a strong acid strong base titration, what is the pH at equivalence
7.00
In a weak Acid, strong base titration, what is the PH at equivalence
7.00> (more basic)
In a weak base, strong acid titration, what is the PH at equivalence?
7.00< (more acidic)
When does the PH = pKa in a titration?
At the halfway point to the equivalence point, meaning at half the added volume of acid/base
What is a polyprotic acid?
an acid that has more than one H+ to donate
Why is Na2CO3 a diprotic base
the CO3 has a 2- charge that allows it to accept the 2 H+
Why do the H’s on H3PO4 come off?
The extended oxygens are very electronegative and pull the electron density towards itself which weakens the bond between the O–H and creates partial charges
Which bonds are very ionizable?
O-H, N-H, H-F
What does a small ka do to an acids ionizability
the smaller ka, the more difficult it is to lose H+ (less acidic, weakest acid)
What is the rule for calculating the pH of a polyprotic acid
When the Ka’s differ by 1000 >, we can calculate the PH from the first ionization reaction
What does the strength of a binary acid depend on
Electronegativity of Y
Bond strength
Which way does acid strength increase across a periodic table
It increases left to right due to increasing electronegativity (doesn’t dissociate as much, the H+ is held more tightly technically a weaker acid because it doesn’t dissociate as much)
What is the trend of bond strength?
It decreases down a row, the acid more weakly held/stronger acidity
What factors affect Oxyacids
Electronegativity of Y and the # of oxygens attached
If the electronegativity is higher on an oxyacid nonmental, is it more acidic (does it dissociate more?/stronger acid)
It is more acidic
the electron density is held near the nonmetal, meaning the H+ is held less tightly
