Mole ratios in chemical reactions

What is the polyatamic ion of borate

How many grams of phosphorus are contained in 5.09 moles of phosphorus?

2-bromo-2-methylbutane undergoes an e1 elimination reaction in the presence of ethanol. in the next reaction only one of the possible products is represented. although the product shown is not the major product of the reaction, notice that there is more than one way it can be produced. complete the mechanism and draw the missing substances.