how many grams of magnesium are required to liberate 250 cm3 of Hydrogen gas from HCL
Mg + 2HCl ==> H2 + MgCl2
You want 250 cc H2. I assume that's at STP. mols H2 = 250 cc x (1 mol/22,400cc) = ?
Convert mols H2 to mols Mg using the coefficients in the balanced equation.
?mol H2 x (1 mol Mg/1 mol H2) =- ? mol H2 x (1/1) = ? mols Mg.
Now convert mols Mg to grams. g = mols x molar mass.
To determine the number of grams of magnesium required to liberate 250 cm3 of hydrogen gas from HCl, we need to use the balanced chemical equation for the reaction between magnesium and hydrochloric acid (HCl).
The balanced chemical equation is as follows:
Mg + 2HCl -> MgCl2 + H2
From this equation, we can see that for every 1 mole of magnesium (Mg) reacted, 1 mole of hydrogen gas (H2) is produced.
To find the number of moles of hydrogen gas, we need to know the conditions of temperature and pressure at which the reaction takes place because the volume of a gas is dependent on these factors. Assuming standard temperature and pressure (STP) conditions at 0 degrees Celsius (273 K) and 1 atmosphere (1 atm) of pressure, 1 mole of any gas occupies 22.4 liters (or 22400 cm3).
Given that the volume of hydrogen gas is 250 cm3, we can now calculate the number of moles of hydrogen gas using the following conversion:
1 mole H2 = 22400 cm3 H2
x moles H2 = 250 cm3 H2
x = (250 cm3 H2) / (22400 cm3 H2/mole H2)
x ≈ 0.011 moles H2
Since the balanced equation tells us that 1 mole of magnesium (Mg) produces 1 mole of hydrogen gas (H2), we can conclude that 0.011 moles of magnesium are required to produce 0.011 moles of hydrogen gas.
Finally, to find the mass of magnesium required, we need to use the molar mass of magnesium, which is approximately 24.31 grams/mole.
Mass of magnesium = (0.011 moles) × (24.31 grams/mole)
Mass of magnesium ≈ 0.267 grams
Therefore, approximately 0.267 grams of magnesium are required to liberate 250 cm3 of hydrogen gas from HCl.
To determine the number of grams of magnesium required to liberate 250 cm3 of hydrogen gas from HCl, you need to know the balanced chemical equation for the reaction between magnesium and hydrochloric acid.
The balanced chemical equation is as follows:
Mg + 2HCl -> MgCl2 + H2
From the equation, we can see that 1 mole of magnesium reacts with 2 moles of hydrochloric acid to produce 1 mole of hydrogen gas.
Now, let's calculate the number of moles of hydrogen gas produced using the following steps:
Step 1: Calculate the molar volume of a gas at room temperature and pressure (RTP). At RTP, 1 mole of any gas occupies 22.4 L or 22,400 cm3.
Step 2: Convert the volume of hydrogen gas from cm3 to L.
Volume in L = Volume in cm3 ÷ 1000
= 250 cm3 ÷ 1000
= 0.250 L
Step 3: Calculate the number of moles of hydrogen gas using the molar volume.
Moles = Volume in L ÷ Molar volume
= 0.250 L ÷ 22.4 L/mol
= 0.0112 mol
Finally, since 1 mole of magnesium reacts with 1 mole of hydrogen gas, we can conclude that to produce 0.0112 moles of hydrogen gas, we would need 0.0112 moles of magnesium.
Step 4: Calculate the mass of magnesium required using its molar mass. The molar mass of magnesium is 24.31 g/mol.
Mass = Moles × Molar mass
= 0.0112 mol × 24.31 g/mol
= 0.272 g
Therefore, to liberate 250 cm3 of hydrogen gas from HCl, approximately 0.272 grams of magnesium are required.