Consider the following chemical equation:
HgO(s) → Hg(l) + O2(g)
How many milliliters of oxygen gas at STP are released from the decomposition of 3.00 g of mercuric oxide?
Same process.
To determine the number of milliliters of oxygen gas released from the decomposition of 3.00 g of mercuric oxide (HgO), we need to use the given chemical equation and convert the given mass of HgO to the volume of O2 gas at standard temperature and pressure (STP).
Step 1: Determine the molar mass of HgO
The molar mass of HgO is calculated by summing the atomic masses of one mercury atom (Hg) and one oxygen atom (O):
HgO = 200.59 g/mol (Hg: 200.59 g/mol, O: 16.00 g/mol)
Step 2: Convert the given mass of HgO to moles
Using the molar mass calculated in Step 1, we can convert the given mass of HgO to moles:
moles of HgO = mass of HgO / molar mass of HgO
moles of HgO = 3.00 g / 200.59 g/mol
Step 3: Use the stoichiometry of the chemical equation
Now we need to use the stoichiometric coefficients from the balanced chemical equation to determine the ratio of moles of HgO to moles of O2. From the chemical equation:
1 mole of HgO produces 1 mole of Hg and 1 mole of O2
So, the moles of O2 gas released would be equal to the moles of HgO.
Step 4: Convert moles of O2 gas to volume at STP
At STP (Standard Temperature and Pressure), one mole of any ideal gas occupies 22.4 liters (or 22,400 milliliters). Therefore, we can use this conversion factor to convert moles of O2 gas to milliliters at STP:
volume of O2 gas at STP = moles of O2 gas x 22,400 mL/mol
Now we can put all the steps together to calculate the final answer.
Step 1: Determine the molar mass of HgO:
molar mass of HgO = 200.59 g/mol
Step 2: Convert the given mass of HgO to moles:
moles of HgO = 3.00 g / 200.59 g/mol = 0.01495 mol
Step 3: Use the stoichiometry of the chemical equation:
moles of O2 gas = moles of HgO = 0.01495 mol
Step 4: Convert moles of O2 gas to volume at STP:
volume of O2 gas at STP = 0.01495 mol x 22,400 mL/mol = 334.88 mL
Therefore, approximately 334.88 milliliters of oxygen gas at STP would be released from the decomposition of 3.00 g of mercuric oxide.