Although we tend to make less use of mercury these days because of the environmental problems created by its improper disposal, mercury is still an important metal because of its unusual property of existing as a liquid at room temperature. One process by which mercury is produced industrially is through the heating of its common ore cinnabar (mercuric sulfide, HgS) with lime (calcium oxide, CaO).
4 HgS(s) + 4 CaO(s) → 4 Hg(l) + 3 CaS(s) + CaSO4(s)
What mass of mercury would be produced by complete reaction of 11.4 kg of HgS?
Answer in kg
To determine the mass of mercury produced, we need to use the balanced chemical equation and the molar masses of the compounds involved.
The balanced chemical equation is:
4 HgS(s) + 4 CaO(s) → 4 Hg(l) + 3 CaS(s) + CaSO4(s)
Looking at the equation, we can see that for every 4 moles of HgS, 4 moles of Hg are produced.
The molar mass of HgS (mercuric sulfide) is:
HgS: 200.59 g/mol
To convert the mass of HgS from kg to g, we multiply by 1000:
11.4 kg × 1000 = 11,400 g
Next, we need to convert the grams of HgS to moles using the molar mass:
11,400 g HgS × (1 mol HgS / 200.59 g HgS) = 56.9 mol HgS
Since the mole ratio between HgS and Hg is 4:4, we can calculate the moles of Hg produced:
56.9 mol HgS × (4 mol Hg / 4 mol HgS) = 56.9 mol Hg
Finally, we convert the moles of Hg to grams using the molar mass of Hg:
56.9 mol Hg × (200.59 g Hg / 1 mol Hg) = 11,397 g Hg
Converting the mass of Hg from grams to kg:
11,397 g ÷ 1000 = 11.397 kg
Therefore, approximately 11.397 kg of mercury would be produced by the complete reaction of 11.4 kg of HgS.
To find the mass of mercury produced by the complete reaction of 11.4 kg of HgS, we can use the balanced chemical equation and stoichiometry.
First, let's find the molar masses:
- The molar mass of HgS (mercuric sulfide) is the sum of the molar masses of mercury (Hg) and sulfur (S), which are 200.59 g/mol and 32.06 g/mol, respectively. So, the molar mass of HgS is 232.65 g/mol.
- The molar mass of Hg (mercury) is 200.59 g/mol.
Now, let's set up the stoichiometric calculation:
1. Convert the mass of HgS (11.4 kg) to grams:
11.4 kg × 1000 g/kg = 11,400 g
2. Convert the mass of HgS to moles using its molar mass:
moles of HgS = mass of HgS / molar mass of HgS
moles of HgS = 11,400 g / 232.65 g/mol
3. Use the stoichiometric ratio from the balanced equation to determine the moles of mercury produced:
According to the balanced equation, 4 moles of HgS produce 4 moles of Hg.
So, moles of Hg = moles of HgS
4. Convert moles of Hg to grams using the molar mass of Hg:
mass of Hg = moles of Hg × molar mass of Hg
5. Convert grams to kilograms:
mass of Hg in kg = mass of Hg / 1000
Now, let's calculate the answer:
moles of HgS = 11,400 g / 232.65 g/mol = 49.07 mol
moles of Hg = 49.07 mol
mass of Hg = 49.07 mol × 200.59 g/mol = 9,839.86 g
mass of Hg in kg = 9,839.86 g / 1000 = 9.84 kg
Therefore, the mass of mercury produced by the complete reaction of 11.4 kg of HgS is approximately 9.84 kg.