To find the partial pressures of neon (Ne) and argon (Ar) in a mixture where neon constitutes 80% of the gas by volume, we can use Dalton's Law of Partial Pressures. According to this law, the partial pressure of each gas in a mixture is equal to the total pressure multiplied by the mole fraction (or volume fraction) of the gas.
Given:
- Total Pressure \( P_{total} = 4.00 , \text{atm} \)
- Volume fraction of Ne = 80% = 0.80
- Volume fraction of Ar = 20% = 0.20 (since 100% - 80% = 20%)
Now we can calculate the partial pressures:
-
Partial pressure of neon (P_Ne): \[ P_{Ne} = P_{total} \times \text{Volume fraction of Ne} \] \[ P_{Ne} = 4.00 , \text{atm} \times 0.80 = 3.20 , \text{atm} \]
-
Partial pressure of argon (P_Ar): \[ P_{Ar} = P_{total} \times \text{Volume fraction of Ar} \] \[ P_{Ar} = 4.00 , \text{atm} \times 0.20 = 0.80 , \text{atm} \]
Thus, the partial pressures are:
- Neon: \( 3.20 , \text{atm} \)
- Argon: \( 0.80 , \text{atm} \)
So, the correct answer is:
3.20 atm Ne and 0.80 atm Ar