5. Jira told Helen that the perfume she used was less dense than water. Helen got a graduated cylinder from the cabinet and found the mass of the cylinder to be 58.35 g. Jira poured 25.0 mL of perfume into the cylinder and massed it again. The combined mass of the cylinder and perfume was 68.80 g. -a. What was the mass of the perfume
-b. What was the density of the perfume?

I think the mass is 35.0 and I can't answer b because I don't know what density is yet

sorry

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 !

thats how its supposed to be