If the strips of MG ribbon are coated with white MgO, would this cause the mass of Mg that you calculate to be too high or too low? Why?
ewf
the mass of Mg will be too low because some of it would have reacted with the oxygen
If the strips of magnesium (Mg) ribbon are coated with white magnesium oxide (MgO), this would cause the calculated mass of Mg to be too high. This is because the coating of MgO adds extra mass to the magnesium ribbon.
When determining the mass of Mg, we assume that the ribbon is pure Mg without any additional compounds. However, when a white coating of MgO is present on the ribbon, it contributes to the total mass measured. MgO is a compound made up of one magnesium atom and one oxygen atom, so when it is present on the ribbon, it adds mass to the overall measurement.
Therefore, in this scenario, if the strips of Mg ribbon are coated with white MgO, the calculated mass of Mg would be artificially higher than the actual mass of pure Mg present in the sample.
When the strips of magnesium (Mg) ribbon are coated with white Magnesium Oxide (MgO), it affects the mass of Mg that you calculate. To understand why, we need to consider the chemical reaction that takes place.
The reaction between Mg and oxygen (O₂) can be represented by the equation:
2 Mg + O₂ → 2 MgO
In this reaction, magnesium combines with oxygen to form magnesium oxide. The molar mass of magnesium (Mg) is 24.31 g/mol, and the molar mass of magnesium oxide (MgO) is 40.31 g/mol.
If the Mg ribbon is coated with MgO, it means that some of the Mg has already reacted with oxygen and formed MgO. As a result, the mass of Mg will appear higher than it actually is because the MgO layer has contributed additional mass.
So, when you calculate the mass of pure Mg, it will be lower than the measured mass due to the presence of MgO. The MgO coating adds an extra mass that belongs to oxygen, not magnesium.
To find the actual mass of Mg, you need to determine the amount of MgO present on the ribbon and subtract it from the total mass. This can be done by either removing the MgO coating chemically or through another method of analysis to differentiate between Mg and MgO.
In conclusion, if the strips of Mg ribbon are coated with white MgO, it would cause the calculated mass of Mg to be too high.