Answer:
y1 = 0.3162
y2 = 0.6838
Explanation:
ok let us begin,
first we would be defining the parameters;
at 25°C;
1-propanol P1° = 20.90 Torr
2-propanol P2° = 45.2 Torr
From Raoults law:
P(1-propanol) = P⁰ × X(1-propanol)
P(1-propanol) = 20.9 torr × 0.45 = 9.405
P(1-propanol) = 9.405 torr
Also P(2-propanol) = P⁰ × X(2-propanol)
P(2-propanol) = 45.2 torr × 0.45
P(2-propanol) = 20.34 torr
but the total pressure = sum of individual pressures
total pressure = 9.405 + 20.34
total pressure = 29.745 torr
given that y1 and y2 represent the mole fraction of each in the vapor phase
y1 = P1 / total pressure
y1 = 9.405/29.745
y1 = 0.3162
Since y1 + y2 = 1
y2 = 1 - y1
∴ y2 = 1 - 0.3162
y2 = 0.6838
cheers, i hope this helps.
Answer:
D
Explanation:
In a Helium (He) atom, the atomic structure of the atom has 2 protons, 2 electrons and 2 neutrons. For an element X to be a Helium (He) atom, it must possess 2 protons. The number of neutrons present will determine its stability either if its probably radioactive or a natural occurring inert gas.
In option 1,
We have H-2. The symbol "H" is used to denote the element hydrogen in the periodic table and hydrogen has only 1 protons and 1 neutron making its mass number 2.
Option 2,
He -2 : here in this option, we have a helium atom, but with mass number of 2 only. Judging from the formula of mass number = protons + neutrons, we already have proton as 2, hence the number of neutrons there is zero (0)
Option 3,
He - 3 : just like in option 2, the only difference here is that the mass number is 3 hence making the number of neutrons just 1.
Option 4,
He - 4 : This option met the requirements of having 2 protons and 2 neutrons making a total of 4 which corresponds to the mass number.
