Using micropipettes for delivery of small volumes pg 5-8

1. if you need to pipette x µl, which micropipette/pipetman would you use?

2. how do you use a micropipette?

3. if you pipette xµl onto a tared weigh boat, what weight should you get in grams? and why?

4. being able to read what micropipettes are set to (pg 6)

5. when would you use a pipet-aid vs a pipetman

6. when should you switch your tip?

7. how do you use the analytical balance?

Hot air balloons float in the air because of the difference in density between cold and hot air. in this problem, you will estimate the minimum temperature the gas inside the balloon needs to be, for it to take off. to do this, use the following variables and make these assumptions: the combined weight of the pilot basket together with that of the balloon fabric and other equipment is w. the volume of the hot air inside the balloon when it is inflated is v. the absolute temperature of the hot air at the bottom of the balloon is th (where th> tc). the absolute temperature of the cold air outside the balloon is tc and its density is ďc. the balloon is open at the bottom, so that the pressure inside and outside the balloon is the same. as always, treat air as an ideal gas. use g for the magnitude of the acceleration due to gravity.

Drug abuse will not lead to physical and psychological dependence. true or false ?

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.