2 grams of potassium (K) reacts with 5 grams of Oxygen (O). According to the Law of Conservation of Mass, how many grams of potassium oxide (K20) will be produced?

5 grams

10 grams

7 grams

2 grams

1 answer

According to the Law of Conservation of Mass, the total mass of the reactants equals the total mass of the products.

In this reaction, you're starting with:

  • 2 grams of potassium (K)
  • 5 grams of oxygen (O)

To find the total mass of the reactants, you add the mass of potassium and oxygen: \[ 2 \text{ grams (K)} + 5 \text{ grams (O)} = 7 \text{ grams (total reactants)} \]

Thus, according to the Law of Conservation of Mass, the mass of potassium oxide (K2O) produced will also be 7 grams.

Therefore, the answer is: 7 grams