Answer:
0.2
Explanation:
Given parameters:
Mass of helium = 0.628g
Mass of neon = 11.491g
Mass of argon = 7.613g
Unknown:
Mole fraction of neon = ?
Solution:
The mole fraction of an element is the number of moles of that element to the total number of moles in the gas mixture.
We need to calculate the number of moles of each element first;
Number of moles = 
Molar mass of Helium = 4g/mol
Molar mass of Neon = 20g/mol
Molar mass of Argon = 40g/mol
Number of moles of He = 
= 0.16moles
Number of moles of Ne = 
= 0.58moles
Number of moles of Ar = 
= 0.19moles
Total number of moles = 0.16moles + 0.58moles + 0.19moles = 0.93moles
Mole fraction Neon = 
= 0.2
Answer:
The temperature is always lower.
Explanation:
The temperature is always lower at the end of the state as compared to beginning of the state. We can see in the given data, the temperature is higher at the beginning i. e. 140 degree Celsius but with the passage of time, the temperature of a state decreases constantly and the temperature at the end is lower i. e. 20 degree Celsius. So we can conclude that the temperature is always lower.
Answer is: H₂O → H⁺ + OH⁻.
Water dissociates (autoionization) to form hydrogen ions (H⁺) and hydroxide (OH⁻) ions. The protons (H⁺) hydrate as hydroxonium ions( H₃O⁺).
The Kw (the ionic product for water) at 25°C is 1·10⁻¹⁴ mol²/dm⁶ or 1·10⁻¹⁴ M². Concentration of hydrogen ions and hydroxide ions in pure water are the same.
The final temperature of the water will be 31.2 °C... i don’t know the second one sorry :(
