Answer: The mole fraction of hydrogen gas at 20°C is 0.975
Explanation:
The information provided includes:
Water vapor pressure at 20°C is 17.5 torr
Total pressure at 20°C = 700.0 torr
Hydrogen gas vapor pressure at 20°C = (700.0 - 17.5) torr = 682.5 torr
To find hydrogen gas's mole fraction at 20°C, we utilize Raoult's law, represented by:

where,
= pressure of hydrogen gas = 682.5 torr
= total pressure = 700.0 torr
= mole fraction of hydrogen gas =?
Substituting the values into the equation yields:

Thus, the mole fraction of hydrogen gas at 20°C equals 0.975
Answer:
The particle's velocity is calculated to be 2 m/s,
Explanation:
Kinetic energy refers to the energy an object possesses due to its movement. The formula for kinetic energy is:

Where:
m = the mass of the object
v = the object's velocity
A particle with mass m has a kinetic energy that is double its mass.




Since the velocity is measured in m/s, we determine that the particle's speed is 2 m/s.
To determine the mass of salt using Avogadro's number, we find the moles of NaCl: 8.24x10²² molecules NaCl divided by 6.022x10²³ molecules NaCl per mole gives 0.14 mole NaCl. We can convert moles to grams of NaCl by multiplying 0.14 mole by 58g NaCl per mole, yielding a total of 8.12 g NaCl.