Most tornadoes carry wind speeds that range from
a. 1 to 105 km per hour.
b. 267 to 322 km per hour.
c. 105 to 177 km per hour.
d. 178 to 266 km per hour.

b is the correct

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !