The mineral dolomite has the formula caco3.mgco3. When dolomite is heated for an extended period of time at elevated temperature it decomposed to give carbon dioxide and a mixture of calcium oxide and magnesium oxide. If a 5.424 g sample of the mineral is heated for several hours at 950 degrees celcius. How many grams should the mixed oxide residue remaining weight?
Well, it seems like Dolomite is having a bit of a heated dilemma here! Let's crunch some numbers and see what we can find out.
First, let's break down the formula of Dolomite: CaCO3.MgCO3. This means that one mole of Dolomite contains one mole of CaCO3 and one mole of MgCO3.
Now, let's calculate the molecular weights:
CaCO3: Ca (40.08 g/mol) + C (12.01 g/mol) + 3 O (16.00 g/mol) = 100.09 g/mol
MgCO3: Mg (24.31 g/mol) + C (12.01 g/mol) + 3 O (16.00 g/mol) = 84.31 g/mol
So, the total molecular weight of Dolomite is 100.09 g/mol (from CaCO3) + 84.31 g/mol (from MgCO3) = 184.40 g/mol.
Now, let's calculate the number of moles in the given 5.424 g sample:
Number of moles = mass / molar mass
Number of moles = 5.424 g / 184.40 g/mol ≈ 0.0294 mol
Since Dolomite is being heated, it will decompose into its respective oxides, Calcium Oxide (CaO), and Magnesium Oxide (MgO).
The molar mass of CaO is 56.08 g/mol, and the molar mass of MgO is 40.31 g/mol.
Since Dolomite has equal moles of CaCO3 and MgCO3, half of the sample will decompose into CaO and the other half into MgO.
So, the mass of the mixed oxide residue remaining can be calculated as follows:
Mass of CaO = (0.0294 mol / 2) x (56.08 g/mol) ≈ 0.818 g
Mass of MgO = (0.0294 mol / 2) x (40.31 g/mol) ≈ 0.593 g
The total mass of the mixed oxide residue is the sum of the masses of CaO and MgO:
Total mass = 0.818 g + 0.593 g ≈ 1.411 g
Therefore, after heating the 5.424 g sample of Dolomite for several hours at 950 degrees Celsius, the mixed oxide residue remaining should weigh around 1.411 grams.
I hope that helps, and remember, even minerals need a little heat to spice up their life!
To find the weight of the mixed oxide residue remaining after heating the dolomite, we need to calculate the amount of carbon dioxide produced and subtract it from the original sample weight.
1. Start by calculating the molar mass of dolomite:
- Calcium carbonate (CaCO₃) molar mass = 40.08 g/mol + 12.01 g/mol + 3(16.00 g/mol) = 100.09 g/mol
- Magnesium carbonate (MgCO₃) molar mass = 24.31 g/mol + 12.01 g/mol + 3(16.00 g/mol) = 84.31 g/mol
2. Calculate the amount of dolomite (CaCO₃.MgCO₃) in moles:
- Moles = mass / molar mass
- Moles = 5.424 g / (100.09 g/mol + 84.31 g/mol) = 0.03230 mol
3. The balanced equation for the decomposition of dolomite is:
CaCO₃.MgCO₃ → CO₂ + CaO + MgO
4. From the equation, we see that for every mole of dolomite, one mole each of CO₂, CaO, and MgO is produced.
5. Calculate the moles of CO₂ produced:
- Moles of CO₂ = 0.03230 mol (since one mole of dolomite produces one mole of CO₂)
6. Calculate the mass of CO₂ produced:
- Mass = moles × molar mass
- Mass = 0.03230 mol × 44.01 g/mol = 1.456 g
7. Subtract the mass of CO₂ produced from the original sample weight to find the weight of the mixed oxide residue:
- Weight of mixed oxide residue = 5.424 g - 1.456 g = 3.968 g
Therefore, the mixed oxide residue remaining after heating the dolomite should weigh approximately 3.968 grams.
To find the weight of the mixed oxide residue remaining after heating, we need to determine the masses of carbon dioxide and calcium oxide and magnesium oxide separately.
1. Start by calculating the molar mass of dolomite:
- CaCO3 has a molar mass of 40.08 + 12.01 + (3 * 16.00) = 100.09 g/mol
- MgCO3 has a molar mass of 24.31 + 12.01 + (3 * 16.00) = 84.31 g/mol
2. Determine the moles of dolomite in the 5.424 g sample by dividing the mass by the molar mass:
- Moles of dolomite = 5.424 g / 100.09 g/mol = 0.05420 mol
3. Carbon dioxide (CO2) is released during the decomposition of dolomite. The molar mass of CO2 is 44.01 g/mol. Calculate the moles of CO2 produced:
- Moles of CO2 = Moles of dolomite = 0.05420 mol
4. Since dolomite decomposes into a mixture of calcium oxide (CaO) and magnesium oxide (MgO), we need to determine the mole ratio of calcium oxide and magnesium oxide produced:
- From the formula, CaCO3:MgCO3 = 1:1
- This means that for every mole of dolomite decomposed, one mole of calcium oxide and one mole of magnesium oxide will be produced.
5. Calculate the moles of calcium oxide (CaO) produced:
- Moles of CaO = Moles of dolomite = 0.05420 mol
6. Calculate the moles of magnesium oxide (MgO) produced:
- Moles of MgO = Moles of dolomite = 0.05420 mol
7. Finally, determine the masses of calcium oxide and magnesium oxide by multiplying their respective moles by their molar masses:
- Mass of CaO = Moles of CaO * Molar mass of CaO
- Mass of MgO = Moles of MgO * Molar mass of MgO
After following these steps, you will have the mass of the mixed oxide residue remaining after heating the dolomite sample at 950 degrees Celsius.
As far as I can tell, dolomite is a 50/50 mixture (mostly) of CaCO3 and MgCO3.
CaCO3 ==> CaO + CO2
MgCO3 ==> MgO + CO2
5.424/2 = approx 2.7 g MgCO3 and approx 2.7 g CaCO3.
Starting with these amounts and the equations above, solve for grams CaO and grams MgO, then add those together.
Post your work if you get stuck.