Which demonstrates a positive impact of chemistry on society?

understanding of how diseases are transmitted

identification and naming of a new species

building of particle accelerators

development of cancer drugs

Answer : Option D) Development of cancer drugs

Explanation : Development of cancer drugs demonstrates a positive impact of chemistry on society. As it opens up new methods and scientific explorations for betterment of human life. It increases the expectancy of life even after getting acquired with cancer as a disease. Development of cancer drugs gives a new hope to the patients of cancer, who thought that it is incurable disease.

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