I have a few questions I was wondering if you guys could help me with. You don't need to solve them, I just want a push in the right direction so I can understand them.

Any and all help is appreciated!---

1. A technician obtained the following results for the concentration (mg/dL) of cholesterol in a blood sample: 240, 252, 242, 238, 239, and 236. The technician re-measured the cholesterol in the same blood sample using a different method. The results were: 233, 231, 222, 235, 239, and 234. At the 95% confidence level is the second method consistently less precise?

I'm pretty certain I need to use a one-tailed F-test for this, but I simply don't know how to do that while comparing with the second method. Any thoughts?

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2a. The

*K*_{sp} of cerium(III) iodate is 1.4×10

^{-11}. What is the molar solubility of cerium(III) iodate in pure water?

I calculated a value of

**0.00085 ***M*. I'm fairly certain this is correct.

2b. What concentration of sodium iodate in solution would be necessary to reduce the cerium concentration in a saturated solution of cerium(III) iodate by a factor of 10 below that calculated in part a?

I'm not sure where to start with this one. I can't just change the molar solubility by dividing it by 10, substituting it into the

*K*_{sp} expression, and solving for [IO

_{3}^{-}]. Any ideas/hints?

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3. A solution is prepared by adding 100.00 mL of 0.10

*M* AgNO3 to 100.00 mL of 0.12

*M* NaCl. (At 25

^{o}C, the

*K*_{sp} for AgCl is 1.8×10

^{-10}.) Calculate the number of milligrams of Ag

^{+} that is

*not* precipitated.

I flat out don't know where to begin on this one.