You are instructed to create 200. mL of a 0.27 M phosphate buffer with a pH of 7.8. You have phosphoric acid and the sodium salts NaH2PO4, Na2HPO4, and Na3PO4 available. (Enter all numerical answers to three significant figures.)
H3PO4(s) + H2O(l) equilibrium reaction arrow H3O+(aq) + H2PO4−(aq)
Ka1 = 6.9 ✕ 10−3
H2PO4−(aq) + H2O(l) equilibrium reaction arrow H3O+(aq) + HPO42−(aq)
Ka2 = 6.2 ✕ 10−8
HPO42−(aq) + H2O(l) equilibrium reaction arrow H3O+(aq) + PO43−(aq)
Ka3 = 4.8 ✕ 10−13
Which of the available chemicals will you use for the acid component of your buffer?
H3PO4
NaH2PO4
Na2HPO4
Na3PO4
Which of the available chemicals will you use for the base component of your buffer?
H3PO4
NaH2PO4
Na2HPO4
Na3PO4
What is the molarity needed for the acid component of the buffer?
What is the molarity needed for the base component of the buffer?
How many moles of acid are needed for the buffer?
How many moles of base are needed for the buffer?
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mol
How many grams of acid are needed for the buffer?
How many grams of base are needed for the buffer?
1 answer