CHM 114 Midterm: Exam 2

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turquoisegnu128

31 Jan 2019

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Chm-115-a: the conjugate acid of hydrogen carbonate ion, hco3. , in aqueous solution is: h2o, h3o, h2co3. Ka = 2. 19 x 10 4: hy. Answers: c, d, a, d, e, a, b. Sample exam 2: which of the following pictures best represents a weak acid (with ka << 1) in aqueous solution? (h2o molecules are not represented. ) Suppose that 0. 1 mole of kcn is added to this solution, with no volume change. 9. 40: calculate the molar solubility of baco3 in water. Ksp = 8. 1 x 10 9: you have a saturated solution of pbi2 in water. Sample exam 2: the drawing shows the distribution of various species in a mixture of hg2+ and cl . (aq) + bi3+(aq: 1, 2, 3, 4, 5, some metallic elements are arranged at the right in an activity series. Select a substance that will reduce ag+ to ag, but will not reduce.

Related Questions

1. What is the activity coefficient for phosphate ion (PO43-), Î³PO43-, in a solution with ionic strength Î¼ = 0.070 M? Calculate using the extended Debye-Huckel equation.

a) 0.126 b) 0.799 c) 0.465 d) 0.505 or e) 1.00

2. For a 0.150 M solution of sodium sulfide, Na₂S, the mass balance for the sulfide is ______ (choose the appropriate). A tip: Anion S^2- is the conjugate base of a diprotic acid, H₂S, which may react with water as a base.

3. Using activities of the ions, calculate the molar solubility of AgCl in an aqueous solution containing an inertelectrolyte with ionic strength Î¼=0.05. K_sp(AgCl)= 1.8Ã10^-10.

4. Which of the following species must have the activity coefficient Î³ = 1 (and hence, the activity = concentration),regardless of the ionic strength of the solution?

(a) HF; (b) F^-; (c) H₃O⁺; (d) Na⁺; (e) Al³⁺; (f) NH₃; (g) H₂O; (h) OH^-.

5. Which of the following ionic salts will not increase the solubility in acidic aqueous solution relative to its solubility in pure water?

(a) NaF; (b) LiCl; (c) Ca(ClO₄)₂; (d) NH₄CH₃COO; (e) KNO₂; (f) Cu(NO₃)₂

Please answer to the best of your ability

Show transcribed image text correctly.Completion and turning in of the entire review will result in an additional +3 pts on your final exam. Show all work to get extra credit. Please contact your instructor for clarification or specific questions. Report the following answers to the following problems with the correct number of significant figures and units: 1. 1 (0521 g 0.4953 0098 61â-24.135ë¯¸+1(120 64 g 4.1847 a)(21st-241530 1 (98.61 C-24.135)120.64g 4.1 21.5Â°C-24.153C) 0.0213548 moles b. (00020334-ern) + ((61210 goles Og) 0.002030 moles 1.02 moles (68.79 mlt29.901 ml) (26.3-0.230) c. 2. You are drying a sample of Bas(POsh. After 5 minutes of drying it weighs 1.2034 g. You continue to dry the sample for another 5 minutes and it now weighs 1.9346 g. What is the percent change in mass? 3. What is the percent mass of carbon in sodium carbonate? 4. What is the density of water at 23.1051Â°c? Use Table 1.1 on page 27 of your lab manual to help. 5. Based on the following reacts, predict the products. Write the balanced molecular equation, total ionic equation, and net ionic equation. All reactions are done in water a. Sodium chloride +silver (I) nitrate b. Calcium bromide + iron (III) sulfate c. Ammonium phosphate+ nickel (II) nitrate d. Hydrochloric acid+ calcium carbonate 6. Write the two balanced chemical reactions for a. Copper (II) oxide reacting with methane under high heat b. Copper (1) oxide reacting with methane under high heat 7. You analyze a mixed sample of copper (1) oxide and copper (II) oxide. The plot and trendline for mass of copper versus mass of mixture yields a slope of 0.8031. What are the mass percents of copper (0) oxide and copper (II) oxide in the mixture?
8. During week 1 of the Empirical Formula Lab you extinguished your "L-tube" flame without waiting 9. 20.00 ml of a 0.30 M potassium phosphate solution is combined with 20.00 mL of a 0.40 M solution 10. An Erlenmeyer flask is capped with a rubber stopper at room temperature (25 C) and atmospheric 11. The first step of the copper cycle lab was reacting solid copper with nitric acid. The copper ends up 12. What are the spectator ions in the 6 reactions performed during the copper cycle lab? for the reaction to cool and did NOT relight the "L-tube" flame. How would this affect your calculated percent mass compared to the true percent mass? of calcium chloride. What is the limiting reactant? What is the identity of the precipitate formed in the reaction? How many grams of product should be collected? pressure (1 atm). What temperature does the Erlenmeyer flask need to be heated to for the stopper to pop off? Assume it needs to exceed external pressure by 0.5 atm to release the stopper. oxidizing to copper (ll). What is the oxidizing reagent in this reaction? 13. The known specific heat capacity of aluminum is o g mo 25.316 g of aluminum is placed in 99.134 of water at a starting temperature of 22.45Â°C. The metal has a AT-84.02c what is the final 14. The AH, of cobalt (U) nitrate is +47.7 kJ/mol. What is the AHr of solid cobalt (1) nitrate? 15. 5.000 g of aluminum (Il) chloride is dissolved in 60.0 mL of water. The temperature changes by 16. Draw the Lewis dot symbols for the following atoms: temperature of the water? ÎÎ(Nouql)--205.00 kJ/mol ÎÎ,(Co2"m)--58.2 kJ/mol 0.331 Â°C. The specific heat capacity of aluminum (III) chloride is 0.903 Wat s AH.? what is ÎÎ a Ð°, Ð½Ðµ Ñ, Ñ c. Ar d. P e. H 17. Draw the Lewis structures for the following molecules: a. NHa b. O2 XeF d. NF

CHM 114 Midterm: Exam 2

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