Hydrogen gas dissolves in palladium with the hydrogen molecules going into the spaces between the metal ions. Determine the molarity, molality, and percent by mass of the H2:Pd solution (d=10.8g/cm)containing 0.94g hydrogen gas dissolved in 215 grams of palladium metal.
% w/w = (Mass H2/total mass)*100
Substitute and solve.
mass H2 = 0.94
mass Pd = 215
mols H2 = grams/molar mass
mass mixture = volume x density. Youhave density and mass, solve for volume.
Then M = moles/L soln.
From those two you can determine
molality = moles/kg solvent
Post your work if you get stuck.
To determine the molarity, molality, and percent by mass of the H2:Pd solution, we need to follow these steps:
Step 1: Calculate the moles of hydrogen gas (H2).
Step 2: Calculate the moles of palladium (Pd).
Step 3: Calculate the molarity of the solution.
Step 4: Calculate the molality of the solution.
Step 5: Calculate the percent by mass of the solution.
Let's calculate them one by one:
Step 1: Calculate the moles of hydrogen gas (H2).
To calculate the moles of H2, we can use the formula:
moles = mass / molar mass
The molar mass of H2 is 2 g/mol. Given that the mass of H2 is 0.94 g, we can calculate the moles of H2:
moles of H2 = 0.94 g / 2 g/mol = 0.47 mol
Step 2: Calculate the moles of palladium (Pd).
To calculate the moles of Pd, we can use the formula:
moles = mass / molar mass
The molar mass of palladium (Pd) is 106.4 g/mol. Given that the mass of Pd is 215 g, we can calculate the moles of Pd:
moles of Pd = 215 g / 106.4 g/mol = 2.02 mol
Step 3: Calculate the molarity of the solution.
The molarity (M) is defined as moles of solute divided by the volume of the solution in liters. However, in this case, since hydrogen gas dissolves in palladium and does not form a true solution, we do not have a volume. Therefore, we cannot calculate the molarity in this case.
Step 4: Calculate the molality of the solution.
The molality (m) is defined as moles of solute divided by the mass of the solvent in kilograms (kg).
mass of Pd = 215 g = 0.215 kg
molality (m) = moles of H2 / mass of Pd
molality (m) = 0.47 mol / 0.215 kg = 2.19 mol/kg
Step 5: Calculate the percent by mass of the solution.
The percent by mass is defined as the mass of solute divided by the mass of the solution, multiplied by 100.
mass of solution = mass of H2 + mass of Pd = 0.94 g + 215 g = 215.94 g
percent by mass = (mass of H2 / mass of solution) * 100
percent by mass = (0.94 g / 215.94 g) * 100 ≈ 0.44%
So, the molarity of the H2:Pd solution is not applicable in this case. The molality of the solution is approximately 2.19 mol/kg. The percent by mass of the solution is approximately 0.44%.