If a chemist analyzes a 3.84g sample containing sand and table sugar, and recovers 1.43g of sand, what percent by mass of table sugar should the chemist report for this sample.

The molecular formula for caffeine is cshion402. which of the following elements is not found in caffeine?

Which of the following represents the ester functional group? a. -coo- b. -cho c. -cooh d. c=o

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.