Which statement accurately describes an object's weight and mass? A. Its weight changes with gravitational force, but its mass does not.
B. Its mass changes with gravitational force, but its weight does not.
C. Both its weight and its mass are the same everywhere in the
universe.
D. Its weight is the same everywhere in the universe, but its mass is
not.

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

answerspecific gravity;

a chemical change results in a new substance being formed; whereas a physical change will result in a different state of matter

explanation: