I think the second choice but I might be wrong
The amu is a unit which means the mass per neutron, So the 74.55 means the mass per mole KCl. So the mole number of 2.330g KCl is 2.330/74.55=0.031 mol. The volume is 0.031/0.1250=0.248 L ≈ 250 mL. So the answer is a.
Answer:
The speed of wavelength is 3.0 ×10³ m/s.
Explanation:
Given data:
De Broglie wavelength = 132 pm (132×10⁻¹² m)
Speed of wavelength = ?
Solution:
Formula:
λ = h/mv
λ = wavelength
h = planck's constant
m = mass of proton
v = speed
now we will put the values in formula.
132×10⁻¹² m = 6.63 ×10⁻³⁴ j.s / 1.67 ×10⁻²⁷ kg × v
v = 6.63 ×10⁻³⁴ j.s / 1.67 ×10⁻²⁷ kg × 132×10⁻¹² m
j = kg m²/s²
v = 6.63 ×10⁻³⁴ kg m²/s / 1.67 ×10⁻²⁷ kg × 132×10⁻¹² m
v = 6.63 ×10⁻³⁴ kg m²/s / 220.44 ×10⁻³⁹ kg.m
v = 0.03×10⁵ m/s
v = 3.0 ×10³ m/s
The speed of wavelength is 3.0 ×10³ m/s.
The fraction of gas phase molecules is calculated by the division of final pressure to the initial pressure.
Fraction =
(1)
Here, initial pressure = 1.0 atm
final pressure = 
First, convert torr into atm
1 atm = 760 torr
final pressure = 
= 
Now, put the value of initial and final pressure in formula (1)
Fraction =
=
Thus, fraction of the gas phase molecules =
