Question

A mixture of 10.0 g of Ne and 10.0 g AR have a total pressure of 1.6 atm. what is the partial pressure of Ne?

Answer 1

The partial pressure of Ne is $\boxed{1.063{\text{ atm}}}$.

Further Explanation:

Dalton’s law:

This law states that partial pressure of any gas is calculated by the multiplication of mole fraction and the total pressure of gas mixture.

The expression for partial pressure of a particular gas is,

${P_{{\text{gas}}}} = {X_{{\text{gas}}}} \cdot {P_{{\text{total}}}}$                                                                         …… (1)

Where,

${P_{\text{gas}$ is the partial pressure of the gas.

${P_{{\text{total}}$ is the total pressure of the mixture.

${X_{{\text{gas}}}$ is the mole fraction of gas.

The formula to calculate moles of component is as follows:

${\text{Moles of component}} = \dfrac{{{\text{Mass of component}}}}{{{\text{Molar mass of component}}}}$                                   …… (2)

Substitute 10.0 g for mass of component and 20.179 g/mol for molar mass of component in equation (2) to calculate moles of Ne.

 $\begin{aligned}{\text{Moles of Ne}} &= \frac{{{\text{10}}{\text{.0 g}}}}{{{\text{20}}{\text{.179 g/mol}}}} \\ &= 0.4956{\text{ mol}} \\\end{aligned}$

Substitute 10.0 g for mass of component and 39.948 g/mol for molar mass of component in equation (2) to calculate moles of Ar.

 $\begin{aligned}{\text{Moles of Ar}} &= \frac{{{\text{10}}{\text{.0 g}}}}{{{\text{39}}{\text{.948 g/mol}}}} \\&= 0.2503{\text{ mol}} \\ \end{aligned}$

Total number of moles can be calculated as follows:

$\begin{aligned}{\text{Total number of moles}} &= \left( {0.4956 + 0.2503} \right){\text{ mol}} \\ &= 0.7459{\text{ mol}} \\\end{aligned}$

The formula to calculate mole fraction of Ne is as follows:

${\text{Mole fraction of Ne}} = \dfrac{{{\text{Moles of Ne}}}}{{{\text{Total number of moles}}}}$                                    …… (3)

Substitute 0.4956 mol for moles of Ne and 0.7459 mol for total number of moles in equation (3).

$\begin{aligned}{\text{Mole fraction of Ne}} &= \frac{{{\text{0}}{\text{.4956 mol}}}}{{{\text{0}}{\text{.7459 mol}}}} \\&= 0.6644 \\\end{aligned}$  

Substitute 0.6644 for ${X_{{\text{gas}}}}$ and 1.6 atm for ${P_{{\text{total}}}}$ in equation (1) to calculate partial pressure of Ne.

$\begin{aligned}{P_{{\text{Ne}}}} &= \left( {0.6644} \right)\left( {1.6{\text{ atm}}} \right) \\&= 1.063{\text{ atm}} \\\end{aligned}$  

Learn more:

1. Calculate the moles of chlorine in 8 moles of carbon tetrachloride: brainly.com/question/3064603
2. ]Which law states the direct relationship between volume and absolute temperature at constant pressure? brainly.com/question/1403211

Answer details:

Grade: Middle School

Subject: Chemistry

Chapter: Gases and the kinetic-molecular theory  

Keywords: partial pressure, mole fraction, Ne, Ar, moles, molar mass, mass, 1.063 atm, 1.6 atm, 0.6644, mole fraction of Ne.

Answer 2

The partial pressure contributed to the overall pressure is proportional to the number of moles of gas particles. Both Neon and Argon are noble gases so there's just 1 atom per molecule. So let's determine how many moles of each we have:
 Atomic weight neon = 20.1797
 Atomic weight argon = 39.948

   Moles neon = 10.0 g / 20.1797 g/mol = 0.495547506 mol
 Moles argon = 10.0 g / 39.948 g/mol = 0.250325423 mol

   So there's a total of 0.495547506 + 0.250325423 = 0.745872929 moles of gas particles. And for neon, it contributes 0.495547506/0.745872929 = 0.664385965 = 66.4385965% of them, so it contributes 66.4385965% of the total pressure. Which is 66.4385965% * 1.6 atm = 1.063017544 atm.

Rounding to 3 significant figures gives 1.06 atm, or 66.4% of the total pressure.