An unknown amount of mercury (II) oxide was decomposed in the lab. Mercury metal was formed and 5.20 L of oxygen was released at a pressure of 0.970 atm and 390.0 K. What was the initial mass of mercury oxide in the sample?

Explanation:

1. Word equation:

2. Balanced molecular equation:

3. Mole ratio

Write the ratio of the coefficients of the substances that are object of the problem:

4. Calculate the number of moles of O₂(g)

Use the equation for ideal gases:

5. Calculate the number of moles of HgO

6. Convert to mass