Question

In a chemical reaction, what does the principle of conservation of mass mean?

Answer 1

`"Garbage in equals garbage out...."`

Explanation:

Conservation of mass is an absolute, underlying, fundamental principle of chemistry. Mass is CONSERVED absolutely in EVERY chemical reaction. And thus a `10*g`, `100*g`, `1000*g` of reactants can yield at most...`10*g`, `100*g`, `1000*g` of products..and most of the time we are not even going to get that.

And see here for more reiteration....

And this principle, which has been followed by every chemical reaction studied in greater or lesser detail, is the reason why educators go to such lengths in insisting that chemical equations are balanced with respect to mass and charge...and why yields should always be calculated...

And this illustrates a valuable life lesson...`"you can't get something for nothing"`, or `"TANSTAAFL"`, `"there ain't no such thing as a free lunch"`...(and I haven't learned this lesson yet!)