How is dna extraction useful to scientists?

I have a website for you to read into that will explain  it further.

DNA extraction allows scientists to get DNA out of its usual habitat and state (contained within cells and associated with proteins). You can’t do much with it when it’s all tangled up with proteins and surrounded by other cellular structures, so extraction is necessary to do further testing.

How is DNA extraction useful for scientists? - Quora

www.quora.com/How-is-DNA-extraction-useful-for-scientists

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