What mass of water is needed to completely react a 8.1 g packet of magnesium
Mg + 2HOH ==> Mg(OH)2 + H2
mols Mg = grams/molar mass = ?
Using the coefficents in the balanced equation, convert mols Mg to mols H2O
Then grams H2O = mols H2O x molar mass H2O = ?
To determine the mass of water needed to completely react with a given mass of magnesium, we need to identify the balanced chemical equation for the reaction between magnesium and water. The reaction can be represented as follows:
Mg + 2H2O -> Mg(OH)2 + H2
From the balanced equation, we can see that one mole of magnesium reacts with two moles of water to form one mole of magnesium hydroxide and one mole of hydrogen gas.
The molar mass of magnesium (Mg) is 24.31 g/mol.
To calculate the amount of water needed, we can proceed as follows:
1. Calculate the number of moles of magnesium:
Moles of Mg = mass of Mg / molar mass of Mg
= 8.1 g / 24.31 g/mol
2. Using the stoichiometry of the balanced equation, we can determine the moles of water needed:
Moles of H2O = 2 x Moles of Mg
3. Calculate the mass of water needed:
Mass of H2O = Moles of H2O x molar mass of H2O
Note:
The molar mass of water (H2O) is 18.02 g/mol.
Let's calculate the mass of water needed:
Moles of Mg = 8.1 g / 24.31 g/mol = 0.3331 mol
Moles of H2O = 2 x 0.3331 mol = 0.6662 mol
Mass of H2O = 0.6662 mol x 18.02 g/mol ≈ 11.99 g
Therefore, approximately 11.99 grams of water is needed to completely react with an 8.1 g packet of magnesium.
To determine the mass of water needed to completely react with a given amount of magnesium, we need to consider the balanced chemical equation for the reaction and use stoichiometry.
The balanced equation for the reaction between magnesium and water is:
2 Mg + 2 H₂O -> 2 Mg(OH)₂ + H₂
From the equation, we can see that 2 moles of magnesium react with 2 moles of water to produce 2 moles of magnesium hydroxide and 1 mole of hydrogen gas.
To find the mass of water needed, we need to calculate the moles of magnesium first. We can use the molar mass of magnesium to convert the given mass of magnesium into moles:
Molar mass of magnesium (Mg) = 24.31 g/mol
Number of moles of magnesium = Mass of magnesium / Molar mass of magnesium
= 8.1 g / 24.31 g/mol
Next, we use the stoichiometry of the reaction to determine the moles of water required. From the balanced equation, we can see that 2 moles of magnesium react with 2 moles of water. Therefore, the moles of water required would be the same as the moles of magnesium:
Number of moles of water = Number of moles of magnesium
= 8.1 g / 24.31 g/mol
Finally, to convert the moles of water into mass, we use the molar mass of water:
Molar mass of water (H₂O) = 18.015 g/mol
Mass of water = Number of moles of water × Molar mass of water
= (8.1 g / 24.31 g/mol) × 18.015 g/mol
Therefore, the mass of water needed to completely react with the 8.1 g packet of magnesium is approximately the calculated value.