Mg and O lab

how will the relative number of moles of mg and o be affected if the following procedural errors are made?

a)crucible is not brought to constant mass before the Mg is added.

b)water is not added after the first heating of Mg, and the entire solid in the crucible is considered to be MgO

c)some of the fluffy white ppt is lost before the crucible is weighed for the last time.

d)in an effort to begin a second sample while the first is cooling, the hot crucible containing the solid from determination 1 is accidently dropped, and a small chip is lost from the crucible.

i said b was a higher value for O because the mass of our product would be higher and we determined the mass of O by subtracting our mass of Mg used, in a previous calculation

i said the decrease in the amount of O for part c because of basically the same reason; we have a smaller product so we would calculate a smaller amount of O

the other two i'm not sure of and am kind of confused.

if you could check mine and help me with the others?
please be specific!thanks!

a. If the xble is not brought to constant weight, meaning that it has some additional mass to lose, I don't think the mols Mg will be affected because the xble is weighed with the Mg cold.

b. Some of the solid is Mg3N2. Since N2 has a lowr mas than O, the Mg3N2 will weigh less than it should as MgO which means the oxygen content appears to be lower.

c. Mass is lower than it should be which makes us think less O was added.

d. Loss of a chip is the same as loss of sample.

Sure, let's go through each procedural error step by step:

a) If the crucible is not brought to constant mass before adding magnesium (Mg), it means that there might be residual moisture or other substances in the crucible. When the Mg reacts with oxygen (O) to form magnesium oxide (MgO), these impurities will also be considered as part of the mass. As a result, the measured mass of Mg and O will be higher than the actual amount present. So, in this case, both the relative number of moles of Mg and O will be overestimated.

b) If water is not added after the first heating of Mg, and the entire solid in the crucible is considered to be MgO, it means that the reaction between Mg and O might not be complete. It is important to add water to ensure that any unreacted Mg is fully converted to MgO. In this situation, the measured mass of O will be lower than the actual amount present because some of the Mg has not reacted. Therefore, the relative number of moles of O will be underestimated, but the number of moles of Mg will remain the same.

c) If some of the fluffy white precipitate (MgO) is lost before the crucible is weighed for the last time, it means that the actual mass of MgO will be lower than the measured mass. As a result, both the relative number of moles of Mg and O will be underestimated because the calculated amount of MgO will be too low.

d) If the hot crucible containing the solid from the first determination is accidentally dropped and a small chip is lost from the crucible, it means that some MgO will be lost. The measured mass of MgO will be lower than the actual amount present, resulting in an underestimation of both the relative number of moles of Mg and O.

To summarize:
a) Overestimation of both Mg and O.
b) Underestimation of O, while Mg remains the same.
c) Underestimation of both Mg and O.
d) Underestimation of both Mg and O due to loss of MgO.

I hope this clarifies things for you, and feel free to ask if you have any more questions!

a) If the crucible is not brought to constant mass before the Mg is added, it means that there might be some residual mass present in the crucible. This will result in an overestimation of the mass of Mg used in the experiment. As a result, the relative number of moles of Mg will be overestimated and the relative number of moles of O will be underestimated. The ratio of moles of Mg to moles of O will still be the same, but the absolute number of moles for each element will be affected.

b) If water is not added after the first heating of Mg, and the entire solid in the crucible is considered to be MgO, it means that any remaining Mg will not react with oxygen to form MgO. This will result in an overestimation of the mass of Mg used in the experiment and an underestimation of the mass of O in the MgO. Therefore, the relative number of moles of Mg will be overestimated and the relative number of moles of O will be underestimated. The ratio of moles of Mg to moles of O will still be the same, but the absolute number of moles for each element will be affected.

c) If some of the fluffy white precipitate (which is likely MgO) is lost before the crucible is weighed for the last time, it means that the measured mass of MgO will be lower than the actual mass. This will result in an underestimation of the mass of O in the MgO and, consequently, an underestimation of the relative number of moles of O. The ratio of moles of Mg to moles of O will remain the same, but the absolute number of moles of O will be affected.

d) If the hot crucible containing the solid from determination 1 is accidentally dropped and a small chip is lost from the crucible, it means that some of the MgO might have been lost. This will result in an underestimation of the mass of MgO, leading to an underestimation of the mass of O as well. Therefore, the relative number of moles of O will be underestimated. The ratio of moles of Mg to moles of O will remain the same, but the absolute number of moles of O will be affected.

In summary:
a) Overestimation of moles of Mg, underestimation of moles of O.
b) Overestimation of moles of Mg, underestimation of moles of O.
c) Underestimation of moles of O.
d) Underestimation of moles of O.

Let's go through each procedural error and determine how it will affect the relative number of moles of Mg and O:

a) If the crucible is not brought to constant mass before the Mg is added, it means there might be additional impurities or moisture present in the crucible. The impurities will contribute to the measured mass when determining the mass of the product (MgO). This will lead to an overestimation of the mass of the product, and consequently, an overestimation of the amount of both Mg and O. Therefore, the relative number of moles of Mg and O would not be affected by this procedural error.

b) If water is not added after the first heating of Mg, and the entire solid in the crucible is considered to be MgO, it means there might still be unreacted Mg present with the MgO. This will lead to an overestimation of the mass of the product, specifically the mass of Mg. However, the mass of O will be correctly determined because it is calculated by subtracting the mass of Mg from the total mass of the product. Therefore, the relative number of moles of Mg will be overestimated, while the number of moles of O will not be affected.

c) If some of the fluffy white precipitate (product) is lost before the crucible is weighed for the last time, it means there will be a decrease in the measured mass of the product, which includes both Mg and O. As a result, the calculated mass of both Mg and O will be lower than the actual values. Therefore, the relative number of moles of Mg and O will be lower than the actual values due to the loss of product.

d) If the hot crucible containing the solid from determination 1 is accidentally dropped and a small chip is lost from the crucible, it means there will be a loss of some of the product (MgO). This loss will result in a decrease in the measured mass of the product, which includes both Mg and O. Consequently, the calculated mass of both Mg and O will be lower than the actual values. Therefore, the relative number of moles of Mg and O will be lower than the actual values due to the loss of product.

In summary:
a) The relative number of moles of Mg and O will not be affected.
b) The relative number of moles of Mg will be overestimated, while the number of moles of O will not be affected.
c) The relative number of moles of Mg and O will be lower than the actual values.
d) The relative number of moles of Mg and O will be lower than the actual values.

I hope this explanation helps! Let me know if you have any further questions.