Astudent did an experiment on the cycling of environmental gases. she placed water and bromthymol blue in each of four test tubes. no other items were placed in tube 1. she placed a snail in tube 2, an aquatic(elodea) in tube 3 and both a snail and elodea in tube 4. then she stoppered the tubes and placed them in bright light for 24 hours. the function of tube 1 in this experiment is to 1. detect the presence of glucose 2. determine the amount of gases in the water 3. demonstrate the transparency of the solution 4. serve as a control

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