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Acid/Base Chem
Statistics
Buffers/Others
100
Two separate solutions, 50.0 mL of 0.200 M HC2H3O2 and 50.0 mL of 1.0 × 10–4 M HCl, are prepared. Which solution has a lower pH?
What is HC2H3O2?
100
Log(x) = 0.8666. What is x? a) 7.3552 b) 7.356 c) 7.35 d) 7.4
What is 7.356 (b)?
100
Which of the following solutions describes a buffer? a) 50 mL 1.0 M HCN and 50 mL 1.0 M KOH b) 50 mL 1.0 M HCN and 25 mL 1.0 M KOH c) 25 mL 1.0 M HCN and 50 mL 1.0 M KOH
What is b?
200
What is the pH of 0.020 M HCl if the activity coefficient of H+ is 0.89 at this ionic strength?
What is 1.75?
200
The calcium content of a mineral was analyzed five times by each of two methods. How would you determine whether the difference in mean values was statistically significant at the 95% CI?
What is the student’s t-test between two means?
200
25 mL of a 0.075 M solution of a weak acid was titrated with 0.10 M NaOH. After the addition of 5.0 mL of NaOH the pH was 4.85. This is the pKa.
What is 5.29?
300
Predict whether a solution of NH4CN will be acidic, basic, or neutral.
What is basic?
300
The following data sets were obtained by two groups using the same methodology.?Set A: 17.8, 19.5, 20.7, 18.6, 21.2? __Set B: 15.8, 17.6, 15.9, 22.1, 17.6, 20.6? What is the number of degrees of freedom for these data sets used in the comparative t-test?
What is 9?
300
What is the Ka for the weak acid system described by the distribution diagram below? (figure 1)
What is 3.2*10^-5
400
In the following mixture of species, which will contribute most strongly to the total [OH-]? 1) 0.010 M NH3 2) 0.010 M Na2SO4 4) 1.0 × 10-8 M Ba(OH)2
What is 1?
400
Two students are performing an experiment to determine the MW of NaHCO3 (MW = 84.0079). Their data is reproduced as shown (figure 2).Which student is more accurate? Which student is more precise?
What is student 1?
400
0.10 M solutions of the following salts are prepared. Which has the highest pH? 1) C2H5NH3-NO3 2) Li2-SO4 3) Na3-PO4 4) K-Br
What is 3?
500
In a soln of zinc cyanide. What will happen to the concentration of zinc ion dissolved in the solution if the pH is lowered without diluting the solution? Support your answer with a chemical equation(s) and remember your acid/base chemistry.
What is increase?
500
Which solution has the highest ionic strength? 1) 0.10 M CaSO4 2) 0.20 M NaCl 3) 0.20 M BaCl2
What is 3?