So, before we do the lab we have to do a lab skills test prior to. I don't want the answers, I just want to know how to set shit up, because, I'm really not getting it. I've got half the answers and have no idea if I'm correct, so if you can tell me if I am and if I went about it the right way, then bully. It's all molarity shit, so I imagine it's pretty basic for someone who has taken chem, but I have not taken chem.

1. Calculate the amount of Tris [Tris(Hydroxomethyl) Aminomethane] needed to make 500 ml of a 1 M stock solution. MW=121.14.

Answer I got: 60.57 grams. Formula: MW*mol*volume

2. Calculate the amount of EDTA (ethylenediamine tetraacetic acid, disodium salt) needed to make 500 ml of a 0.5 M stock solution. FW=372.2

Answer I got: 93.05 grams. Same formula as above.

3. Calculate the total volume of solution needed to get an 80% solution from 100 ml of 95% ETOH (Ethanol). [Note: Use absolute (100%) ethanol, but be aware that shortly after the bottle is opened, absolute ethanol becomes 95%. If a bottle has been opened, calculate the total volume of solution needed to get an 80% solution from 100 ml of a 95% solution.]

118.75 ml (I'm thinking this is wrong, whereas I'm pretty sure about the above two). Formula: Concentration of stock agent/final concentration needed=Final volume needed/volume of stock reagent. Which is a formula given in the lab manual.

4. You have 300 ul [sic. I'm assuming microliters] of DNA solution in TE buffer. You wish to add salt to precipitate your DNA. You have a 3M NaOAc solution. You wish to bring your DNA solution to 0.3M NaOAc.

No clue.

5. How much solute is required to make 300 ml of 0.8 M CaCl_{2}?

I imagine I use a variant of the formula in 1 and 2.

6. How would you prepare 500% (w/v) solution of NaCl?