1.When mixing 45mL of 0.65M acetic acid with 65mL of 0.45M NaOH the resulting mixture is
a. basic
b. neutral
c. acidic
d. pH < 7
e. both c and d
The correct answer is b. neutral right?
2.The concentration of [OH-] in Al(OH)3 is 2.6 x 10^-5. What is the concentration of Al3+?
a.7.8 x 10^-5
b.5.2 x 10^-5
c.8.7 x 10^-6
d.7.8 x 10^-15
The answer is c right
3 answers
2 is right. 1 is wrong. For 1, it is true that the number of mols acid - number of mols base; however, remember that the salt formed hydrolyzes.
So what would the correct answer for 1 be?
You tell me. If I let HAc stand for acetic acid and NaAc is sodium acetate, then
HAc + NaOH ==> NaAc + H2O
Now you write the equation for the hydrolysis of the acetate ion (Ac^-) and the answer will be obvious. (Hint: hydrolysis means reacting with water)
HAc + NaOH ==> NaAc + H2O
Now you write the equation for the hydrolysis of the acetate ion (Ac^-) and the answer will be obvious. (Hint: hydrolysis means reacting with water)