The burning of the magnesium becomes uncontrolled (it burn brightly. Oops! How will this procedural error affect the reported mole ratio of magnesium to oxygen in the analysis? Explain.
You haven't described the procedure you have used in detail but from what I know about the usual procedure, if the ribbon of Mg catches fire and burns brightly the chances are good that convection currents associated with the brightly burning Mg ribbon will carry away some of the oxide that is formed; thus, the true weight of the MgO will not be measured when the product is weighed.
In a hurry to complete the experiment, Josh did not allow all the magnesium to react. Will his reported magnesium to oxygen ration be reported too high or too low? Explain
Part of the Mg burns to MgO but part of the Mg stays in the original state. That means the final product contains a mixture of MgO and Mg but Josh THINKS it is all Mg and O combined.
mass oxide - mass initial mg will be too low (since not all of the Mg has combined with O) so the Mg to O ratio will be too high. That is, the experimental result will be mg2O, Mg3O, or something like that. The way to do this yourself is to assume you had 24 g Mg and it combined with 16 g Oxygen to form 40 g MgO. Then back up and say, "ok, only 12 g Mg combined, so the final product will be 12 g Mg and 12+8 g MgO so you have a mass of 32 g which you think is the oxide. Experimentally, 32-24 = 8 g oxygen combined, 8 g is 0.5 mole, 24 g Mg is 1 mole so we have MgO1/2 and that is a ratio of Mg2O in small whole numbers. So the ratio Mg to O will be too high? Check my thinking.
John forgot to add the few drops of water resulting in the presence of some Mg3N2 in the final solid product. Will her reported magnesium to oxygen mole ratio be reported too high or too low? Explain. Hint: The Mg: N mass ratio is 1:0.38, and the Mg:O mass ratio is 1:0.66.
The procedural error of the uncontrolled burning of magnesium will affect the reported mole ratio of magnesium to oxygen in the analysis. Let's break down the explanation step by step:
1. What is a mole ratio?
- A mole ratio represents the ratio of the number of moles of one substance to another substance in a balanced chemical equation. It helps us understand the stoichiometry, or the quantitative relationships, between reactants and products in a chemical reaction.
2. How is the mole ratio determined?
- To determine the mole ratio, we need to know the balanced chemical equation for the reaction we are studying. For the burning of magnesium in oxygen, the balanced equation is:
2 Mg + O2 → 2 MgO
This equation tells us that for every 2 moles of magnesium (Mg), we need 1 mole of oxygen (O2), and this will produce 2 moles of magnesium oxide (MgO).
3. How does the uncontrolled burning affect the mole ratio analysis?
- In a controlled experiment, we would carefully measure the mass of magnesium and the volume of oxygen, ensuring that they react completely according to the balanced equation. However, in the case of uncontrolled burning, some magnesium may not react completely or may react with more oxygen than necessary. This can happen when the burning becomes too vigorous and creates excess heat, causing some magnesium to escape as smoke or sparks without reacting fully with oxygen.
4. What will be the impact on the mole ratio analysis?
- The uncontrolled burning leads to an inaccurate mole ratio analysis because the actual quantity of magnesium and oxygen involved in the reaction deviates from what was intended. If magnesium escapes as smoke or sparks without reacting, we will end up with less magnesium than expected. As a result, the measured mole ratio of magnesium to oxygen will be lower than the actual mole ratio predicted by the balanced equation.
- Additionally, if the uncontrolled burning causes excess heat, it can lead to a higher proportion of magnesium reacting with oxygen, resulting in a higher-than-expected mole ratio of magnesium to oxygen. This could occur if the heat caused some magnesium to burn more vigorously or if it created a localized area where the magnesium was exposed to a higher concentration of oxygen.
Overall, the uncontrolled burning leads to incomplete or excessive reactions, resulting in an inaccurate mole ratio. It is important to ensure controlled conditions to obtain reliable and precise results.