The first step in the industrial recovery of zinc from the zinc sulfide ore is roasting, that is, the conversion of ZnS to ZnO by heating. 2 ZnS(s) + 3 O2(g) → 2 ZnO(s) + 2 SO2(g) ΔH = -879 kJ/mol
Calculate the heat evolved (in kJ) per gram of ZnS roasted.
You have 879 kJ/mol and you have 2 mols in the equation so the reaction produces 2 x 879 kJ. How many grams ZnS are there are 2 moles?
Thank You
To calculate the heat evolved per gram of ZnS roasted, we need to use the given molar reaction enthalpy and the molar mass of ZnS.
1. First, calculate the molar mass of ZnS:
- The molar mass of Zn (zinc) is 65.38 g/mol.
- The molar mass of S (sulfur) is 32.06 g/mol.
- The molar mass of ZnS is (65.38 g/mol) + (32.06 g/mol) = 97.44 g/mol.
2. Now, we can calculate the heat evolved per mole of ZnS roasted:
- ΔH = -879 kJ/mol (given)
- Heat evolved per mole of ZnS = ΔH = -879 kJ/mol.
3. To calculate the heat evolved per gram of ZnS, we need to divide the heat evolved per mole of ZnS by the molar mass of ZnS:
- Heat evolved per gram of ZnS = (Heat evolved per mole of ZnS) / (Molar mass of ZnS)
- Heat evolved per gram of ZnS = (-879 kJ/mol) / (97.44 g/mol).
Now, plug in the values and calculate the answer.