a 9.6 gram piece of clean magnesium burned completely in 6.4 grams of pure oxygen and the product was allowed to cool at room temperature and pressure. Determine the reaction mole ratio and hence the formula for the oxide
To determine the reaction mole ratio and the formula for the oxide, we need to first find the moles of magnesium and moles of oxygen involved in the reaction.
1. Calculate the moles of magnesium:
Molar mass of Mg = 24.31 g/mol
moles of Mg = mass of Mg / molar mass of Mg = 9.6 g / 24.31 g/mol ≈ 0.394 mol
2. Calculate the moles of oxygen:
Molar mass of O2 = 32.00 g/mol
moles of O2 = mass of O2 / molar mass of O2 = 6.4 g / 32.00 g/mol = 0.20 mol
The reaction mole ratio is the ratio of the moles of the reactants magnesium and oxygen. From the balanced chemical equation, we know that the ratio is 2 moles of Mg to 1 mole of O2.
Therefore, the mole ratio of magnesium to oxygen is 2:1.
Now, we can determine the empirical formula of the oxide. The empirical formula represents the simplest whole number ratio of the elements in a compound.
Since the ratio of Mg to O2 is 2:1, the empirical formula for the oxide is MgO.
To find the reaction mole ratio and hence the formula for the oxide, we need to start by determining the moles of both magnesium and oxygen involved in the reaction.
1. Calculate the moles of magnesium (Mg):
Molar mass of Mg = 24.31 g/mol
Moles of Mg = mass of Mg / molar mass of Mg
Moles of Mg = 9.6 g / 24.31 g/mol ≈ 0.3944 mol
2. Calculate the moles of oxygen (O2):
Molar mass of O2 = 32.00 g/mol
Moles of O2 = mass of O2 / molar mass of O2
Moles of O2 = 6.4 g / 32.00 g/mol = 0.200 mol
Now that we have determined the moles of both magnesium and oxygen, we can establish their mole ratio.
Mole ratio (Mg : O2) = Moles of Mg / Moles of O2
Mole ratio (Mg : O2) = 0.3944 mol / 0.200 mol ≈ 1.972
The mole ratio indicates that 1 mole of magnesium reacts with approximately 1.972 moles of oxygen.
Now, to determine the formula for the oxide, we need to simplify this ratio to whole numbers. To do this, we multiply both numbers by a small whole number to obtain a simpler ratio.
Since the ratio is close to 2, we can multiply both numbers by 2 to obtain the simplest whole number ratio:
Mole ratio (Mg : O2) = 1.972 ≈ 2 : 4
The simplified mole ratio (Mg : O2) is 1 : 2. This suggests that the formula for the oxide formed is MgO.
To determine the reaction mole ratio and the formula for the oxide, we need to use the concept of stoichiometry and the mole ratios in the balanced chemical equation.
First, we write the balanced chemical equation for the reaction of magnesium with oxygen:
2 Mg + O2 → 2 MgO
From the equation, we can see that 2 moles of magnesium react with 1 mole of oxygen to produce 2 moles of magnesium oxide.
Given that 9.6 grams of magnesium and 6.4 grams of oxygen are used in the reaction, we need to convert these masses to moles. The molar mass of magnesium is approximately 24.31 g/mol, and the molar mass of oxygen is approximately 32.00 g/mol.
Number of moles of magnesium = mass of magnesium / molar mass of magnesium
= 9.6 g / 24.31 g/mol
≈ 0.394 moles
Number of moles of oxygen = mass of oxygen / molar mass of oxygen
= 6.4 g / 32.00 g/mol
= 0.200 moles
Now, we can use the mole ratios from the balanced equation to determine the ratio of moles of magnesium to moles of oxygen consumed in the reaction.
Mole ratio of magnesium to oxygen = 0.394 moles / 0.200 moles
= 1.97
Since the mole ratio is approximately 1.97, we can round it off to 2. This means that for every 2 moles of magnesium, 1 mole of oxygen is consumed.
Finally, we use the mole ratio to determine the empirical formula of the oxide. In this case, the empirical formula is the simplest whole number ratio of the atoms present in the compound.
From the mole ratio, we can say that the empirical formula of the oxide is MgO.
Therefore, the formula for the oxide formed when 9.6 grams of magnesium reacts with 6.4 grams of oxygen is MgO.