Dark energy and dark matter seem over analyzed, although they are no different than gravity and wind. Dark energy can be the pulling caused by black holes, stars, and large planets. Dark matter also is just the effect of cosmic dust and debris pushed from explosions but also pulling caused by distant gravitational bodies.
To be able to calculate the number of moles for this problem, for simplicity, we assume that it is an ideal gas. We use the equation PV = nRT. We do as follows:
PV = nRT
n = PV / RT
n = 1(100000) / 0.08206 (27 + 273.15)
n = 4060.04 mol
An c.ionic bond forms when a cation transfers its extra electron to an anion who needs it.
For example compound magnesium chloride (MgCl₂) has ionic bond (<span>the </span>electrostatic attraction<span> between oppositely charged </span><span>ions)</span>. Magnesium transfers two electrons (became positive cation) to chlorine (became negative anion).
Answer: The vapor pressure of a mixture of 80 g of ethanol and 97 g of methanol at 293 K is 78.3 torr.
Explanation:
According to Raoult's law, the vapor pressure of a component at a given temperature is equal to the mole fraction of that component multiplied by the vapor pressure of that component in the pure state.
and 
where, x = mole fraction in solution
= pressure in the pure state
According to Dalton's law, the total pressure is the sum of individual pressures.
moles of ethanol=
moles of methanol= 
Total moles = moles of ethanol + moles of methanol = 1.7 +3.0 = 4.7
Thus the vapor pressure of a mixture of 80 g of ethanol and 97 g of methanol at 293 K is 78.3 torr.
