Read the excerpt from levitt and dubner’s freakonomics. driving around the parks that encircle washington, he solicited customers with a simple pitch: early in the morning, he would deliver some bagels and a cash basket to company’s snack room; he would return before lunch to pick up the money and the leftovers. it was an honor-system commerce scheme, and it worked. within a few years, feldman was delivering 8,400 bagels a week to 140 companies and earning as much as he had ever made as a research analyst. he had thrown off the shackles of cubicle life and made himself happy. the authors prove feldman’s success by describing

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2