Based on the data obtained from the reaction, the following conclusions can be made;
- according to the law of conservation of mass, the mass of the product was higher than the reactant because of the mass of oxygen added during the combustion.
- the percent yield is less than 100% because of loss in mass of either reactants or products.
- the errors could have occurred during the weighing and transfer of reactants and products
- repeated measurements are required in order to improve accuracy
Equation of the reaction is given below:
- 2 Mg + O₂ ----> 2 MgO
Trial 1
Mass of empty crucible with lid = 26.698 (g)
Mass of Mg metal, crucible, and lid = 27.040 (g)
Mass of MgO, crucible, and lid = 27.198 (g)
Mass of metal = 27.040 - 26.698 = 0.342
Mass of MgO = 27.198 - 26.698 = 0.500
<h3>Moles of Mg used</h3>moles of Mg = mass/molar mass
- molar mass of Mg = 24 g
moles of Mg = 0.342/24 = 0.01425
<h3>Moles of MgO expected</h3>Based on the equation of reaction;
moles of MgO expected = 0.01425
moles of MgO produced = mass/molar mass
- molar mass of MgO = 40 g/mol
moles of MgO produced = 0.500/40 = 0.0125
<h3>Percent yield</h3>- Percent yield = (moles of MgO produced/moles of MgO expected) * 100%
Percentage yield = 0.0125/0.01425 * 100%
Percent yield of MgO = 87.7%
Trial 2
Mass of empty crucible with lid = 26.691 (g)
Mass of Mg metal, crucible, and lid = 27.099 (g)
Mass of MgO, crucible, and lid = 27.361 (g)
Mass of metal = 27.099 - 26.691 = 0.408
Mass of MgO = 27.361 - 26.691 = 0.670
<h3>Moles of Mg used</h3>moles of Mg = mass/molar mass
- molar mass of Mg = 24 g
moles of Mg = 0.408/24 = 0.0170
<h3>Moles of MgO expected</h3>Based on the equation of reaction;
moles of MgO expected = 0.0170
- moles of MgO produced = mass/molar mass
molar mass of MgO = 40 g/mol
moles of MgO produced = 0.670/40 = 0.01675
<h3>Percent yield</h3>- Percent yield = (moles of MgO produced/moles of MgO expected) * 100%
Percent yield = 0.01675/0.0170 * 100%
Percent yield of MgO = 98.5%
Average percent yield = (87.7 + 98.5)% / 2
Average percent yield = 89.0%
Based on the data obtained from the reaction, the following conclusion can be made;
- according to the law of conservation of mass, the mass of the product was higher than the reactant because of the mass of oxygen added during the combustion.
- the percent yield is less than 100% because of loss in mass of either reactants or products.
- the errors could have occurred during the weighing and transfer of reactants and products
- repeated measurements are required in order to improve accuracy
Learn more about law of conservation of mass at: brainly.com/question/1824546
