Part A Which of the following statements about chemical formulas is FALSE? Which of the following statements about chemical formulas is FALSE? The subscripts represent the relative mass of each type of atom in the compound. Different compounds made of the same elements have different subscripts. The subscripts represent the relative number of each type of atom in the compound. The subscripts do not change for a given compound. All of the statements are true.

Option (a) is the correct answer.

Explanation:

Subscript present in chemical formula of a compound represents the number of atoms of the element actually present in it.  

For example, in the subscripts present in it are 7, 7, 1, and 2.

A subscript is not responsible for determining the relative mass of each type of an atom because a subscript simply represents the number of atoms of each type of an element participating or combining with other atoms of a compound.

Thus, we can conclude that the statement subscripts represent the relative mass of each type of atom in the compound, is false.

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