Volumetric Analysis of an In answering these questions, you may use your textboo
ID: 942217 • Letter: V
Question
Volumetric Analysis of an In answering these questions, you may use your textbook, lab from class. You may not confer with any other members of the class nor use your electronic device to search for answers. These questions must lab. Complete and balance the following acid-base reaction: H_2SO_4 (aq) + NaOH(aq) Calculate the Molarity (moles per liter) of H_2SO_4, solution if 40.00 mL of H_2SO_4, required 42.10 rnL of 0.0600 M NaOH to reach a pink phenolphthalein endpoint during a titration. Show work - must have correct number of significant figure for full credit. A student determined her H,S04 solution concentration to be 0.0610 M. the actual concentration of the solution was 0.0650 M. the student claims that her major error was due to addition of too much NaOH past the endpoint. Does her analysis seem reasonable given the fact that her experimental value was lower than the actual concentration? Explain your reasoning. What error would result in the calculated sulfuric acid Molarity value (too high, too low. or no effect) if you had residual water in the pipet when pipetting the 25.00 mL acid into the flask? Explain your reasoning.Explanation / Answer
1a. H2SO4 + 2NaOH -> Na2SO4 + 2H2O
1b. 0.0421L * 0.06M = 0.002526 moles of NaOH
0.002526 moles of NaOH * (1 mol H2SO4 / 2 mol NaOH) = 0.001263 moles of H2SO4
Molarity = 0.001263 moles / 0.04 L = 0.031575 M
2. It doesn't seem reasonable because if more volume is added of the same NaOH concentration, it means that more moles of H2SO4 reacted, hence increasing the molarity value of H2SO4 solution, until reaching the endpoint. It could be reasonable to think that more NaOH was missing, or that there were impurities or water in the mixing flask.
3. The resulting molarity will be lower due to if residual water is present, less moles of acid will be present in the same value, hence, having a lower concentration.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.