Base your answer to this question the information below. Cobalt-60 is commonly used as a source of radiation for the prevention of food
spoilage. Bombarding cobalt-59 nuclei with neutrons produces the
nuclide cobalt-60. A food irradiation facility replaces the cobalt-60, a
source of gamma rays, when the radioactivity level falls to 1/8 of its initial
level. The nuclide cesium-137 is also a source of radiation for the
prevention of food spoilage. 28. Identify one emission spontaneously
released by a cobalt-60 nucleus. *

oh it is true if thats what you are asking

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