a sample of natural gas at stp is 78% ch4 and 22% c2h6 by volume. how many moles of each gas are presented in 2 L of the mixture.assume ideal gas behavior

To find the number of moles of each gas in the mixture, we need to use the ideal gas equation:

PV = nRT

Where:
P = pressure (at STP, it is 1 atm)
V = volume (2 L in this case)
n = moles of gas
R = ideal gas constant (0.0821 L•atm/mol•K)
T = temperature (at STP, it is 273 K)

Let's start by calculating the number of moles of CH4 (methane) in 2 L of the mixture.

Since the volume percentage of CH4 is given, we'll use it to find the volume of CH4 in the mixture:

Volume of CH4 = 78% * 2 L = 1.56 L

Now, we can calculate the moles of CH4 by dividing its volume by the molar volume:

n(CH4) = Volume of CH4 / Molar volume

The molar volume at STP is 22.4 L/mol.

n(CH4) = 1.56 L / 22.4 L/mol

n(CH4) ≈ 0.07 mol

So, there are approximately 0.07 moles of CH4 in 2 L of the mixture.

Next, let's calculate the number of moles of C2H6 (ethane):

Volume of C2H6 = 22% * 2 L = 0.44 L

n(C2H6) = Volume of C2H6 / Molar volume

n(C2H6) = 0.44 L / 22.4 L/mol

n(C2H6) ≈ 0.02 mol

Therefore, there are approximately 0.02 moles of C2H6 in 2 L of the mixture.

In summary, there are approximately 0.07 moles of CH4 and 0.02 moles of C2H6 in 2 L of the natural gas mixture.