These Assignments Should Be a Review for You

CHEM 2001 … skill test Name……………………………………….

These assignments should be a review for you. Find if you have difficulty with the assignments, you need to correct this problem immediately. I would advise that you get out your book and notes from 1202 or whatever book/notes you have from your freshman chemistry course and review them. If you need to get a tutor, do so. It is imperative that you hone your quantitative skills right off the bat - we will be using them all semester.

Some of the question below may require you to review the set of review notes.

1-1. Express the following quantities with standard abbreviations for units and prefixes. For example, 10-5 amperes would be 10 mA.

(a) 10-10 joules

(b) 4.317 28 X 10 -8 coulombs

(d) 10-10 meter

(e) 2.1 X 10 13 watts

(f) 48.3 X 10-20 moles

1-2. If 0.345 L of aqueous solution with a density of 1.10 g/mL contains 10.7 μg of pesticide, express the concentration of pesticide in (a) ppm and (b) ppb.

1-3. Hot perchloric acid is a powerful (and potentially explosive) reagent used to decompose organic materials and solubilize them for chemical analysis.

(a) How many grams of perchloric acid, HClO4, are contained in 1000.0 g of 70.5 wt %

aqueous perchloric acid?

(b) How many grams of water are in 1000.0 g of the solution in a?

1-4. How many grams of 12.5 wt % NaOH (FM 40.00) should be diluted to 1.00 L to make 0.10 M NaOH?

1-5 A dilute aqueous solution containing 1 ppm of solute has a density of 1.08 g/mL.

Express the concentration of solute in g/L, μg/L, μg/mL, and mg/L.

1-6. The concentration of C20H42 (FM 282.55) in winter rainwater has been found to be 0.35 ppb. Assume that the density of the winter rainwater is effectively 1.00 g/mL; find the molar concentration of C20H42.

1-7. Cesium chloride is used to prepare dense solutions required for isolating cellular

components with a centrifuge. A 40.0 wt % solution of CsCl (FM 168.36) has a density of 1.4g/mL.

(a) Find the molarity of the CsCl.

(b) How many milliliters of the concentrated solution should be diluted to 800 mL to

make 0.100 M CsCl?

1-8. What do the symbols TD and TC mean on volumetric glassware? Is temperature

important here in your definitions?

1-9. Water from a 5-mL pipet was drained into a weighing bottle whose empty mass was

9.974 g to give a new mass of 14.974 g at 26 ºC. Find the volume of the pipet.

1-10. Water was drained from a buret between the 0.12- and 15.78-mL marks. The apparent volume was 15.78 – 0.12 = 15.66 mL. Measured in air at 25 ºC, the mass of water delivered was 15.569 g. What was the true volume?

1-11. You are to make a 1.500 M solution of Cu(NO3)2 in water. Assuming you will make

0.60000 L of this solution, how would you prepare it? And I mean exactly how would you prepare it?

1-12. If we took EXACTLY 1.000 mL of the copper nitrate solution in problem 1-11 and placed it in 49.000 mL of water and mixed it, then took 2.000 mL of this solution and placed it in 98.000 mL of water, what is the concentration (in mole/L or M) of Cu2+ and NO3- in the final solution? Explain why the two ion concentrations are different.

1-13. What is the pH of a 10-4 M hydrochloric acid solution?

1-14. Knowing that acetic acid (HOAc) is a weak electrolyte or acid, and you know that the equilibrium constant for HOAc <----> OAc- + H+ is Ka = 1.75 x 10-5, what is the pH of a 1.0000 F solution of acetic acid?