Answer: 386.0 g/mol
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
where,
= relative lowering in vapor pressure
i = Van'T Hoff factor = 1 (for non electrolytes)
= mole fraction of solute =
Given : 21.47 g of compound X is present in 233.8 g of diethyl ether
moles of solute (X) =
moles of solvent (diethyl ether) =
= mole fraction of solute =
The molecular weight of this compound is 386.0 g/mol
Answer:
B)
Explanation:
Mutations are changing in chromosomes.
Answer : The correct option is, (c) 79.62
Explanation :
The formula used for percent humidity is:
..........(1)
The formula used for relative humidity is:
...........(2)
where,
= partial pressure of water vapor
= vapor pressure of water
p = total pressure
First we have to calculate the partial pressure of water vapor by using equation 2.
Given:
Relative humidity = 80 % = 0.80
Now put all the given values in equation 2, we get:
Now we have to calculate the percent humidity by using equation 1.
Therefore, the percent humidity is 79.62 %
Answer:
The correct answer is option C.
Explanation:
Kr is the symbol of a noble gas named krypton.It belongs to the group 18 of the periodic table in which all the elements are less reactive.
These noble gases are highly inert and less reactive due to:
- Completely filled electronic configuration in their valence shell.
- High ionization enthalpies.
- Positive value of electron gain enthalpy.
Answer:
ΔH = +26.08 kJ/mol
Explanation:
The change in enthalpy (ΔH) is given in J/mol, and can be calculated for dissolution by the equation:
ΔH = m(water)*Cp*ΔT/n(solute)
The mass of water is the density multiplied by the volume
m = 1g/mL * 25.0mL = 25.0 g
The number of the moles is the mass divided by the molar mass. Knowing the molar masses of the elements:
N = 14 g/mol x 2 = 28
H = 1 g/mol x 4 = 4
O = 16 g/mol x 3 = 48
NH₄NO₃ = 80 g/mol
n = 1.25/80 = 0.015625 mol
So,
ΔH = 25*4.18*(25.8 - 21.9)/0.015625
ΔH = 26,083.2 J/mol
ΔH = +26.08 kJ/mol