Answer: The statement that unit for temperature should be Kelvin and the unit for volume should be milliliters is False.
Explanation:
According to the ideal gas equation:
P = Pressure of the gas = 1 atm (at STP)
V= Volume of the gas = 22.4 L (at STP)
T= Temperature of the gas = 273 K (at STP)
R= Gas constant = ?
n= moles of gas= 1 mol
Thus the unit for temperature should be Kelvin and the unit for volume should be Liters.
In this case, according to the Raoult's law, we can find the mole fraction of 79 wt% benzene and 21 wt% toluene at 50 °C in the vapor phase as follows:
However, we first have to calculate the mole fractions in the solution as follows (b stands for benzene and t for toluene):
Next, we calculate the total pressure as follows, according to the Dalton's law:
Finally, the mole fractions of the vapor phase turn out:
Learn more:
Answer:
Fluorine, chlorine, bromine and iodine are grouped together because they have the same number of valence electrons.
Explanation:
Fluorine, chlorine, bromine and iodine are all found in group 7, which is the second-last column from the right. Group 7 elements are also called the "Halogens" family.
The group number also tells you the number of valence electrons that the elements have in that group. Valence electrons mean the outermost electrons (See picture).
For example, fluorine has two shells (the circles with dots on them). The outermost electrons, or valence electrons, are the dots on the biggest circle. There are 7 dots, so there are 7 valence electrons, which corresponds with Group "7".
A full shell (except the for first shell) is when there are 8 dots. Since 7 is so close to 8, Halogens are very reactive.
Fluorine, chlorine, bromine and iodine all have 7 valence electrons and are in the Halogens family, which are very reactive.
