Nitrogen-12 was able to be used in an experiment, but it took 243 seconds to get the nitrogen from the reactor to the laboratory. If 12.0mg of nitrogen-12 was removed from the reactor, how many mg were placed in the reaction vessel 243 seconds later if the half-life of nitrogen-12 is 81 seconds?

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 !

i don't know people like to fight everywhere rip.

the answer is 75.0%.