For the acids, use the formula pH =-log[H*]. (Because HCI has 1 H* ion per formula unit, [H*] equals the molarity.) For water, use what you know about the pH of neutral solutions. For the bases, examine and
extend the pattern.

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 !

the solar system used to have much dust particles option no d