Dimercaprol (HSCH2CHSHCH2OH) was developed during World War I as an antidote to arsenic-based poison gas and is used today to treat heavy-metal poisoning. It binds the toxic element and carries it out of the body. (a) If each molecule binds one arsenic (As) atom, how many atoms of As could be removed by 515 mg of dimercaprol

2.50x10²¹ atoms

Explanation:

First we convert the given mass of dimercaprol to moles, to do so we calculate its molar mass:

515 mg equal 0.515 g

As one dimercaprol molecule binds to one As atom, one mol of dimercaprol reacts with one mol of As.

So we convert those 4.146 x 10⁻³ mol of As to atoms, using Avogadro's number:

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >