How many moles of magnesium are needed to react with 16 g of O2?
2 MgO (s) + O2 (g) → 2 MgO (s)
To determine how many moles of magnesium are needed to react with 16 g of O2, we need to use the balanced chemical equation and the molar masses of magnesium (Mg) and oxygen (O2).
Step 1: Write down the balanced chemical equation.
2 MgO (s) + O2 (g) → 2 MgO (s)
Step 2: Determine the molar mass of O2.
The molar mass of O2 is 32 g/mol since oxygen (O) has a molar mass of 16 g/mol, and there are two oxygen atoms in O2.
Step 3: Calculate the number of moles of O2.
To find the number of moles of O2, we divide the given mass by the molar mass:
Number of moles = Mass / Molar mass
Number of moles = 16 g / 32 g/mol = 0.5 mol
Step 4: Use the stoichiometry of the balanced equation to find the moles of Mg.
According to the balanced equation, the ratio of moles of Mg to moles of O2 is 2:1. So, for every 2 moles of MgO, we need 1 mole of O2.
Since there are 0.5 moles of O2, we can calculate the moles of Mg using the ratio:
Number of moles of Mg = 0.5 mol O2 * (2 mol MgO / 1 mol O2) = 1 mol
Therefore, 1 mole of magnesium (Mg) is needed to react with 16 g of O2.
To determine the number of moles of magnesium needed, we need to use the stoichiometry of the balanced equation.
The balanced equation tells us that 2 moles of magnesium (Mg) react with 1 mole of oxygen gas (O2) to produce 2 moles of magnesium oxide (MgO).
1. First, we need to calculate the number of moles of oxygen gas (O2) present in 16 g.
The molar mass of oxygen gas (O2) is 32 g/mol (2 * 16 g/mol). We can use this information to calculate the number of moles of O2:
Number of moles of O2 = mass of O2 / molar mass of O2
= 16 g / 32 g/mol
= 0.5 mol
So, we have 0.5 moles of oxygen gas (O2).
2. Now, according to the balanced equation, the stoichiometric ratio between magnesium (Mg) and oxygen gas (O2) is 2:1. This means that for every 2 moles of magnesium, we need 1 mole of oxygen gas.
Since the ratio is 2:1, we can calculate the number of moles of magnesium required:
Number of moles of Mg = (0.5 mol O2) / (1 mol O2 / 2 mol Mg)
= 0.25 mol Mg
Therefore, 0.25 moles of magnesium (Mg) are needed to react with 16 g of oxygen gas (O2).