Ag=108. Câu 1 : Khái niệm nào sau đây đúng nhất về este? A. Este là những chất chỉ có trong dầu, mỡ động thực vật. B. Este là những chất có chứa nhóm -COO-. C. Khi thay nhóm -OH ở nhóm cacboxyl của axit cacboxylic bằng nhóm OR (R khác H) được este.

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?

Write the formula for the following chemicals. 7. e. trinitrogen tetraoxide a calcium phosphate f. magnesium acetate b. potassium sulfide g nickel(iii) cyanide c carbon dioxide h. silver sulfate d. cobalt(ii) chloride

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.