what is the theoretical yield in grams of MgO if 2.54g Mg metal reacts with excess O2
2Mg + O2 ==> 2MgO
mols Mg = grams/atomic mass = ?
Convert mols Mg to mols MgO. Use 1 mol Mg = 1 mol MgO.
Now convert mols MgO to grams MgO. grams = mols x molar mass
82.9g
To calculate the theoretical yield of MgO, you need to determine the balanced chemical equation for the reaction and then use stoichiometry to find the moles of MgO produced. Finally, convert moles to grams using the molar mass of MgO.
The balanced chemical equation for the reaction between Mg metal and O2 is:
2 Mg + O2 -> 2 MgO
From the equation, you can see that 2 moles of Mg react with 1 mole of O2 to produce 2 moles of MgO.
First, calculate the number of moles of Mg using its molar mass (24.31 g/mol):
Moles of Mg = Mass of Mg / Molar mass of Mg
Moles of Mg = 2.54 g / 24.31 g/mol
Next, determine the moles of MgO that can be produced using the stoichiometric ratio:
Moles of MgO = Moles of Mg * (2 Moles of MgO / 2 Moles of Mg)
Moles of MgO = Moles of Mg
Finally, convert moles of MgO to grams using the molar mass of MgO (40.31 g/mol):
Theoretical yield of MgO (in grams) = Moles of MgO * Molar mass of MgO
Now, you can substitute the values you calculated:
Theoretical yield of MgO = Moles of Mg * Molar mass of MgO
Please note that this calculation assumes a complete reaction and does not account for any other factors that may affect the actual yield, such as impurities or side reactions.