If 6.57 grams of iron are reacted with an excess of hydrochloric acid, then hydrogen gas and 14.63 grams of iron (II) chloride are obtained. Calculate the
theoretical yield and the percent yield. Fe + HCl + H + FeCl2

Maria wants to determine which type of disinfectant kills the most bacteria. which of the following is the best way for maria to determine this? a. ask ten different companies that make disinfectants which type is best. b. put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate. c. interview ten different people to determine which type of disinfectant they prefer. d. put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

Tin has ten stable isotopes. the heaviest, 124sn, makes up 5.80% of naturally occuring tin atoms. how many atoms of 124sn are present in 82.0 g of naturally occurring tin? what is the total mass of the 124sn atoms in this sample?

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer