A buffer consists of 0.34 M NaH2PO4 and 0.28 M Na2HPO4. Given that the values for...
A buffer consists of 0.24 M NaH2PO4 and 0.47 M Na2HPO4. Given that the K values for H3PO4 are, Ka1 = 7.2 x 10-3, Ka2 = 6.3 x 10-8, and Ka3 = 4.2 x 10-13, calculate the pH for this buffer.
A buffer consists of 0.24 M NaH2PO4 and 0.47 M Na2HPO4. Given that the K values for H3PO4 are, Ka1 = 7.2 x 10-3, Ka2 = 6.3 x 10-8, and Ka3 = 4.2 x 10-13, calculate the pH for this buffer. I know that the answer is 7.49 because pH = -log(6.3 x 10-8) + log(0.47/0.24). What I want to know is WHY 6.3 x 10-8 was used instead of Ka1 or Ka3. Thanks.
Be sure to answer all parts. A buffer consists of 0.12 M NaHPO4 and 0.26 M Na2HPO4. Phosphoric acid is a triprotic acid (Ka1 7.2 X 103, K2-6.3 x 108, K3 - 4.2 x 1013) (a) Which K, value is most important to this buffer? Ka1 is most important. K z is most important. Kn3 is most important. (b) What is the buffer pH?
Phosphoric acid, H3PO4, is a triprotic acid with the following acid dissociation constants: Ka1 = 7.5 × 10-3 Ka2 = 6.2 × 10-8 Ka3 = 4.2 × 10-13 Which of the following combinations would be best for preparing a pH 7 buffer? a. H3PO4 and NaH2PO4 b. H3PO4 and HCl c. Na2HPO4 and Na3PO4 d. NaH2PO4 and Na2HPO4 e. H3PO4 and Na3PO4
You are instructed to create 400. mL of a 0.40 M phosphate buffer with a pH of 6.4. 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) H3O+(aq) + H2PO4−(aq) Ka1 = 6.9 ✕ 10−3 H2PO4−(aq) + H2O(l) H3O+(aq) + HPO42−(aq) Ka2 = 6.2 ✕ 10−8 HPO42−(aq) + H2O(l) H3O+(aq) + PO43−(aq) Ka3 = 4.8 ✕ 10−13 Which of the available chemicals will you use...
A buffer consists of 0.27 M KHCO3 and 0.33 M K2CO3. Given that the K values for H2CO3 are, Ka1 = 4.5 x 10-7 and Ka2 = 4.7 x 10-11, calculate the pH for this buffer.
A buffer consists of 0.53 M KHCO3 and 0.59 M K2CO3. Given that the K values for H2CO3 are, Ka1 = 4.5 x 10-7 and Ka2 = 4.7 x 10-11, calculate the pH for this buffer.
You are instructed to create 400. mL of a 0.39 M phosphate buffer with a pH of 6.2. 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) = H30+ (aq) + H2P04 (aq) Kai = 6.9 x 10-3 H2PO4 (aq) + H20(1) =H30+ (aq) + HPO42-(aq) Ka2 = 6.2 x 10-8 HPO42-(aq) + H20(I) = H30+(aq) + PO43-(aq) Ka3 = 4.8 x 10-13 Which of...
a) What are the concentrations of Na2HPO4 and NaH2PO4 in a 0.30 M phosphate buffer solution pH 7.0? Use pKa 6.82 b) Describe how you would prepare 250 mL of the buffer in part (a) given that you have available to you a 1.0 M stock solution of NaH2PO4 and solid Na2HPO4(FW 141.96 g/mol). Provide your answer in milliliters of NaH2PO4 and grams of Na2HPO4. c) Suppose you use 100 ml of this buffer in an experiment and 0.003 mol...
You are instructed to create 400. mL of a 0.39 M phosphate buffer with a pH of 6.2. You have phosphoric acid and the sodium salts NaH2PO4, Na2HPO4, and Na3PO4 available. (Enter all numerical answers to three significant figures.) H3PO4(s) + H20(1) =H30+ (aq) + H2PO4 (aq) Kai = 6.9x10-3 H2PO4 (aq) + H20() = H30+(aq) + HPO42- (aq) Ka2 = 6.2x 10-8 HPO42-(aq) + H20(I) = H30+(aq) + PO43-(aq) Ka3 = 4.8 x 10-13 Which of the available chemicals...