Solutions of hydrogen in palladium may be formed by exposing...

Solutions of hydrogen in palladium may be formed by exposing Pd metal to $\mathrm{H}_{2}$ gas. The concentration of hydrogen in the palladium depends on the pressure of $\mathrm{H}_{2}$ gas applied, but in a more complex fashion than can be described by Henry's law. Under certain conditions, 0.94 g of hydrogen gas is dissolved in 215 g of palladium metal (solution density $=10.8 \mathrm{g} \mathrm{cm}^{3}$ ). (a) Determine the molarity of this solution. (b) Determine the molality of this solution. (c) Determine the percent by mass of hydrogen atoms in this solution.

Solutions of hydrogen in palladium may be formed by exposing Pd metal to $\mathrm{H}_{2}$ gas. The concentration of hydrogen in the palladium depends on the pressure of $\mathrm{H}_{2}$ gas applied, but in a more complex fashion than can be described by Henry's law. Under certain conditions, 0.94 g of hydrogen gas is dissolved in 215 g of palladium metal (solution density $=10.8 \mathrm{g} \mathrm{cm}^{3}$ ).
(a) Determine the molarity of this solution.
(b) Determine the molality of this solution.
(c) Determine the percent by mass of hydrogen atoms in this solution.

Key Concepts

Molarity

Molarity is a concentration unit that measures the number of moles of a solute per liter of solution. It is particularly useful in reactions and processes where the solution volume is a critical parameter, and it is calculated by dividing the moles of dissolved substance by the total volume of the solution, typically adjusted to standard units of liters.

Molality

Molality is a concentration unit defined as the number of moles of solute per kilogram of solvent. It is useful in situations where temperature variations are significant because, unlike molarity, molality depends solely on the mass of the solvent and not on the volume of the solution, which can change with temperature.

Mass Percent Composition

Mass percent composition is a way of expressing the concentration of a component in a mixture or solution by showing the ratio of the mass of that component to the total mass of the mixture, multiplied by 100. This calculation is straightforward and useful for comparing the relative amounts of components in a sample regardless of the total volume or mass.

Transcript

00:01 Hello, everyone.

00:01 This is ricky, and today we're working on problem number eight from chapter 11.

00:06 And we're given that under certain conditions, we can make a solution of hydrogen in palladium.

00:16 But the concentration of hydrogen that in the palladium depends on the pressure of hydrogen gas applied.

00:25 All right.

00:26 So we're also given that 0 .94 grams of hydrogen is dissolved in 215 grams of palladium metal.

00:36 All right, so first, let's calculate molarity.

00:51 Then let's also keep in, let's also remember that the density of the solution is equal to 1 .8 grams per cubic centimeter.

01:10 All right.

01:12 So to start off, let's go with, let's start by calculating the number of moles of hydrogen in the solution.

01:26 So we have 0 .94 grams of hydrogen multiplied by 1 mole over the molar mass of hydrogen is 1 .008 grams.

01:53 And this is equal to 0 .9333 moles.

02:05 Of hydrogen.

02:13 So next we have we have to determine the volume of the solution.

02:28 And so volume is equal to the total mass over its density.

02:42 And that is equal to 0 .94 grams hydrogen plus 215 grams grams of gladium all over 1 .8 grams per cubic centimeter.

03:02 And we get that the volume of our solution is 120 cubic centimeters, which we need to convert to liters.

03:13 And so we have one liter is equal to 1 ,000 cubic centimeters.

03:20 And so we find that the total volume of our solution is 120 liters...

Please give Ace some feedback