Law of Conservation of Mass Wkst.doc - Law of Conservation of Mass ... - Free Printable

Let’s work through the problem step by step.

The question is:
“Hydrogen and oxygen react to form water. How much water would form if 14.8 grams of hydrogen reacted with 34.8 grams of oxygen?”

We are told to use the Law of Conservation of Mass, which says:
> In a chemical reaction, matter is neither created nor destroyed. So, the total mass of the reactants (what you start with) equals the total mass of the products (what you end up with).

In this case:
- Reactants = hydrogen + oxygen
- Product = water

So, if all the hydrogen and oxygen react completely, then:

Mass of water formed = mass of hydrogen + mass of oxygen

That’s:

14.8 g (hydrogen) + 34.8 g (oxygen) = ?

Let’s add them:

14.8
+34.8
------
49.6

So, 49.6 grams of water should be formed — assuming both reactants are completely used up and there’s no leftover.

But wait — we should check if one reactant might run out first (limiting reactant). The problem doesn’t give us a balanced equation or ask for mole calculations, and since it’s under “Law of Conservation of Mass” and part of a worksheet that seems to focus on simple addition (as seen in earlier parts), it’s likely expecting us to just add the masses.

Also, looking at the context — this is probably an introductory chemistry problem where they want students to apply conservation of mass directly without worrying about stoichiometry yet.

So, unless told otherwise, we assume both reactants fully combine.

Final calculation:
14.8 + 34.8 = 49.6 grams

✔ Double-check:
14.8 + 34.8 → 14 + 34 = 48, and 0.8 + 0.8 = 1.6 → 48 + 1.6 = 49.6 ✔️

---

Final Answer:
49.6 grams