In: Chemistry
Given the following acids or bases. 1) H2PO4 -2 2) CH3NH3 a. Write the reactions for each of the above b. Write the K expressions for the reactions and look up the K for each of the above. c. What is the conjugate of each of the above? (there may be more than one) d. Write the reaction for the conjugate interacting with water. e. Write the K expressions for the reactions that involves the conjugate and calculate the value of the K.
1) H2PO4 - 2) CH3NH3+
a. Write the reactions for each of the above
1) H2PO4 –
H2PO4 - --- > H+ + HPO42 –
HPO4 -2 --- > H+ + PO4 -3
2) CH3NH3+
CH3NH3+ -à CH3NH2 +H+
b. Write the K expressions for the reactions and look up the K for each of the above.
1) H2PO4 –
H2PO4 - --- > H+ + HPO42 –
K = [H+][HPO42 –]/[ H2PO4 - ]
HPO4 -2 --- > H+ + PO4 -3
K = [H+][PO4 3 –]/[ HPO42 - ]
2) CH3NH3+
CH3NH3+ -à CH3NH2 +H+
K= [CH3NH2][H+]/[ CH3NH3+]
c. What is the conjugate of each of the above? (there may be more than one)
H2PO4 - conjugate pair ---- > HPO42 –
HPO4 -2 conjugate pair---- > PO4 -3
CH3NH3+ conjugate pair CH3NH2
d. Write the reaction for the conjugate interacting with water.
HPO42 – + H2O --- > H2PO4 – + OH-
H2PO4 – + H2O --- > H3PO4 + OH-
CH3NH2 + H2O --- > CH3NH3+ OH-
e. Write the K expressions for the reactions that involves the conjugate and calculate the value of the K.
HPO42 – + H2O --- > H2PO4 – + OH-
K= [H2PO4 –][OH-]/[ HPO4 2–]
H2PO4 – + H2O --- > H3PO4 + OH-
K= [H3PO4 ][OH-]/[ PO4 3–]
CH3NH2 + H2O --- > CH3NH3+ OH-
K= [CH3NH2]/[ CH3NH3+][OH-]