Hide Tools
Janice needs to have a gastro-intestinal study. So she is given 375 mg of radiocontrast dye containg Barium-142. The half-life of Ba-142 is
10.6 minutes and its decay is followed by X-ray. After one half-Life, drag and drop answer here of Ba-142 remains. After 31.8 minutes,
drag and drop answer here of Ba-142 remains. After drag and drop answer here half-lives, 11.7 mg of Ba-142 remains. After
drag and drop answer here minutes, 0.366 mg of Ba-142 remains. Finally, after approximately 3.5 hours - drag and drop answer here half-
lives, only 0.000358 mg remains. The dye is no longer visible to the X-ray and Janice's study is over.

Straightforward questions answered in the powerpoint slidesreaction: heating the starting materials under refluxwhat does it mean to heat under reflux? why do we choose water as the reflux solvent? what are boiling chips used for? why do we put a condenser on top of the reaction? why do we add heat and let the reaction stir for 30 minutes? why do we add sulfuric acid to the reaction after it cools as opposed to when it’s still hot? separation: filtration of precipitatewhy don’t we do an aqueous and organic extraction in the separatory funnel? why do you rinse the salicylic acid on the filter with ice cold water? purification: recrystallization of salicylic acid (no hot filtration needed)what is the difference in the amount of room temperature water vs. boiling water needed to dissolve the salicylic acid (assume a 1.2 gram yield of salicylic acid)? remember, in the lab if you need x ml of boiling water to dissolve a solid, then you should add a little more (definitely no more than 1.5 times the theoretical amount) to ensure it doesn’t recrystallize prematurely.analysis: melting point of salicylic acidwhat can you conclude if the melting point of the salicylic acid you just synthesized is 152-155oc and the 1: 1 mix of your product and “synthetic” salicylic acid is 151-154oc?

Which type of fossil does this image depict?

Is heavenly controller dating someone?