Answer:
0.534
Explanation:
Mole fraction can be calculated using the formula:
Mole fraction = number of moles of solute ÷ number of moles of solvent and solute (solution).
In this question, solute is dimethyl ether while the solvent is methanol.
Mole (n) = mass (M) ÷ molar mass (MM)
Mole of solute (dimethyl ether) = 148.5 ÷ 46.07
= 3.22moles.
Mole of solvent (methanol) = 90 ÷ 32.04
= 2.81moles.
Total moles of solute and solvent = 3.22 + 2.81 = 6.03moles.
Mole fraction of dimethyl ether = number of moles of dimethyl ether ÷ number of moles of solution (dimethyl ether + methanol)
Mole fraction = 3.22/6.03
= 0.534
Magnesium is in Group 2 (sometimes called Group II or 2A). Since it is in Group 2 it will have 2 valence electrons. When you draw the Lewis structure for Magnesium you'll put two "dots" or valance electrons around the element symbol (Mg).
Since gas molecules average velocity depends on temperature, oxygen molecules at 25°C are moving faster than oxygen molecules at 0 °C.
According to the kinetic theory of gases, the molecules of a gas are in constant random motion and collide frequently with each other and the walls of the container.
The average speed of gas molecules depends on temperature and molar mass as shown by the relation;
vrms = √3RT/M
The following statement are true among the options provided;
- Oxygen molecules at 25°C are moving faster than oxygen molecules at 0 °C
- Gases exert pressure by colliding with container walls
The following are false among the options provided;
- All hydrogen molecules are moving with the same velocity
- Nitrogen gas exerts more pressure than hydrogen gas because nitrogen molecules are heavier than hydrogen molecules.
- Nitrogen molecules remain suspended in the atmosphere because they are not attracted to Earth by gravitational forces.
Learn more: brainly.com/question/6505878